@misc{roblesnavarro_tipping_the_2024, author={Robles-Navarro, A., Jerabek, P., Schwerdtfeger, P.}, title={Tipping the balance between the bcc and fcc phase within the alkali and coinage metal groups}, year={2024}, howpublished = {journal article}, doi = {https://doi.org/10.1002/anie.202313679}, abstract = {Why the Group 1 elements crystallize in the body-centered cubic (bcc) structure, and the iso-electronic Group 11 elements in the face-centered cubic (fcc) structure, remains a mystery. Here we show that a delicate interplay between many-body effects, vibrational contributions and dispersion interactions obtained from relativistic density functional theory offers an answer to this long-standing controversy. It also sheds light on the Periodic Table of Crystal Structures. A smooth diffusionless transition through cuboidal lattices gives a detailed insight into the bcc→fcc phase transition for the Groups 1 and 11 elements.}, note = {Online available at: \url{https://doi.org/10.1002/anie.202313679} (DOI). Robles-Navarro, A.; Jerabek, P.; Schwerdtfeger, P.: Tipping the balance between the bcc and fcc phase within the alkali and coinage metal groups. Angewandte Chemie - International Edition. 2024. vol. 63, no. 1, e202313679. DOI: 10.1002/anie.202313679}} @misc{warfsmann_applying_wash_2023, author={Warfsmann, J., Puszkiel, J.A., Passing, M., Krause, P.S., Wienken, E., Taube, K., Klassen, T., Pistidda, C., Jepsen, J.}, title={Applying wash coating techniques for swelling-induced stress reduction and thermal improvement in metal hydrides}, year={2023}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2023.169814}, abstract = {The storage of hydrogen in metal alloys as an alternative to hydrogen storage in pressurized or liquid form has the advantage of high volumetric storage capacity and less complex storage systems due to lower pressure and moderate temperature conditions. The later leads to an improved safety and reduced cost of the storage vessel. However, when considering their utilization in hydrogen storage tanks, swelling-induced stress and heat management are challenges that still require to be addressed. Several strategies have been published in the past to address these problems, however it can be challenging to scale them up. In this work, we propose an easily scalable approach to overcome these drawbacks. The commercially available AB2 room-temperature metal alloy Hydralloy C5 was modified by applying a wash coating-like methodology. The surface of the metal alloy was coated with a mixture of a conductive material like expanded natural graphite (ENG) or aluminum and the elastomeric ethylene-vinyl acetate copolymer (EVA). The performance of this modified metal alloy was investigated by in situ measurement of hydrogen capacity, heat dissipation and swelling-induced stress during 50 hydrogenation/dehydrogenation cycles. The coated metal alloy maintained a satisfactory hydrogen capacity with slightly improved heat dissipation. The swelling-induced stress behavior of the treated material was greatly improved. Especially the addition of a mixture of 10 wt% ENG and 10 wt% EVA allowed to completely compensate for the swelling-induced stress during hydrogenation.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2023.169814} (DOI). Warfsmann, J.; Puszkiel, J.; Passing, M.; Krause, P.; Wienken, E.; Taube, K.; Klassen, T.; Pistidda, C.; Jepsen, J.: Applying wash coating techniques for swelling-induced stress reduction and thermal improvement in metal hydrides. Journal of Alloys and Compounds. 2023. vol. 950, 169814. DOI: 10.1016/j.jallcom.2023.169814}} @misc{dematteis_insitu_neutron_2023, author={Dematteis, E.M., Barale, J., Capurso, G., Deledda, S., Sørby, M.H., Cuevas, F., Latroche, M., Baricco, M.}, title={In-situ neutron diffraction during reversible deuterium loading in Ti-rich and Mn-substituted Ti(Fe,Mn)0.90 alloys}, year={2023}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2022.168150}, abstract = {Hydrogen is an efficient energy carrier that can be produced from renewable sources, enabling the transition towards CO2-free energy. Hydrogen can be stored for a long period in the solid-state, with suitable alloys. Ti-rich TiFe0.90 compound exhibits a mild activation process for the first hydrogenation, and Ti(Fe,Mn)0.90 substituted alloys can lead to the fine tuning of equilibrium pressure as a function of the final application. In this study, the crystal structure of TiFe(0.90-x)Mnx alloys (x = 0, 0.05 and 0.10) and their deuterides has been determined by in-situ neutron diffraction, while recording Pressure-Composition Isotherms at room temperature. The investigation aims at analysing the influence of Mn for Fe substitution in Ti-rich Ti(Fe,Mn)0.90 alloys on structural properties during reversible deuterium loading, which is still unsolved and seldom explored. After activation, samples have been transferred into custom-made stainless-steel and aluminium alloy cells used for in-situ neutron diffraction experiments during deuterium loading at ILL and ISIS neutron facilities, respectively. The study enables remarkable understanding on hydrogen storage, basic structural knowledge, and support to the industrial application of TiFe-type alloys for integrated hydrogen tank in energy storage systems by determining the volume expansion during deuteration. Furthermore, the study demonstrates that different contents of Mn do not significantly change the volumetric expansion during phase transitions, affecting only the deuterium content for the γ phase and the cell evolution for the β phase. The study confirms that the deuterated structures of the γ phase upon absorption, β and α phase upon desorption, correspond to S.G. Cmmm, P2221 and Pm-3m, respectively.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2022.168150} (DOI). Dematteis, E.; Barale, J.; Capurso, G.; Deledda, S.; Sørby, M.; Cuevas, F.; Latroche, M.; Baricco, M.: In-situ neutron diffraction during reversible deuterium loading in Ti-rich and Mn-substituted Ti(Fe,Mn)0.90 alloys. Journal of Alloys and Compounds. 2023. vol. 935, 168150. DOI: 10.1016/j.jallcom.2022.168150}} @misc{le_experimental_and_2023, author={Le, T., Santhosh, A., Bordignon, S., Chierotti, M., Jerabek, P., Klassen, T., Pistidda, C.}, title={Experimental and computational studies on the formation of mixed amide-hydride solid solutions for CsNH2–CsH system}, year={2023}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.rineng.2023.100895}, abstract = {In this study, experimental determination and computational prediction are combined to investigate the formation of a mixed amide-hydride solid solution for the CsNH2–CsH system in a wide compositional range. The experimentally obtained results strongly indicate that a complete amide-hydride solid solution Cs(NH2)xH1-x with a stable cubic structure is achievable when the molar fraction of amide (x) is lower than 0.9. These results validate and confirm our data computationally via first-principles calculations, including the simulations of infrared (IR) and nuclear magnetic resonance (NMR) spectra for structures of various compositions as well as the determination of the dipolar coupling constants. Both the computed vibrational frequencies and 1H chemical shifts of CsNH2 and CsH moieties in the Cs(NH2)xH1-x (x = 0.2, 0.5, 0.8, 1) solid solution structures agree with the experimental IR and 1H MAS NMR data of the mixed xCsNH2+(1-x)CsH samples, confirming the formation of the solid solutions. The closest interproton distance in the homogeneous Cs(NH2)0·5H0.5 solid solution is computed to be 3.67 Å, which is larger than that of the known Rb(NH2)0·5H0.5 solid solution (3.29 Å). This work's combination of theoretical research and experimentation provides a suitable framework for the structural analysis and property estimation of other M-N-H solid solutions.}, note = {Online available at: \url{https://doi.org/10.1016/j.rineng.2023.100895} (DOI). Le, T.; Santhosh, A.; Bordignon, S.; Chierotti, M.; Jerabek, P.; Klassen, T.; Pistidda, C.: Experimental and computational studies on the formation of mixed amide-hydride solid solutions for CsNH2–CsH system. Results in Engineering. 2023. vol. 17, 100895. DOI: 10.1016/j.rineng.2023.100895}} @misc{elsenberg_tuning_aerosol_2023, author={Elsenberg, A., Emmler, T., Schieda, M., Gärtner, F., Klassen, T.}, title={Tuning Aerosol Deposition of BiVO4 Films for Effective Sunlight Harvesting}, year={2023}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s11666-023-01550-0}, abstract = {Bismuth vanadate (BiVO4) offers high photon efficiencies in solar photo-anodes, due to its suitable semiconductor band gap energies and associated visible light absorption. In well-tuned conditions, such anodes enable green hydrogen generation in photoelectrochemical water splitting cells. Bismuth vanadate films have to ensure high efficiencies in electron/hole pair generation and sufficiently high rates of charge transfer to the conducting substrate and the electrolyte, respectively. Thus, the tuning of coating properties has to aim for high phase purity, good layer integrity as well as optimum diffusion path lengths. In order to explore the potential of aerosol deposition to produce BiVO4 films with high photoelectrochemical activity and to elucidate influences on microstructure and application properties, powder sizes and spraying parameters had to be tailored. By ball milling over durations of up to 20 min, particles sizes in the range from 8.3 down to 0.6 µm were obtained. With respect to spray conditions, the process gas pressure was varied from 1.0 to 2.1 bar corresponding to gas flow rates of 10-40 l/min. The wide range of powder sizes and parameters in aerosol deposition allowed for developing a window of deposition in order to derive the most promising combinations for layer build-up. Optimum parameter sets in application on stainless steel substrates were transferred to FTO-coated glass substrates for backlit cell layouts. The thickness and conductivity of the layers were adjusted to a layer thickness range of 200-500 nm in order to achieve maximum photocurrents. The production of homogeneous, large-scale prototypes demonstrates that aerosol deposition is suitable for processing layers for solar energy harvesting with high photo current densities of up to 3.55 mA/cm2.}, note = {Online available at: \url{https://doi.org/10.1007/s11666-023-01550-0} (DOI). Elsenberg, A.; Emmler, T.; Schieda, M.; Gärtner, F.; Klassen, T.: Tuning Aerosol Deposition of BiVO4 Films for Effective Sunlight Harvesting. Journal of Thermal Spray Technology. 2023. vol. 32, 352-362. DOI: 10.1007/s11666-023-01550-0}} @misc{vaidhyanathankrishnamurthy_iridium_based_2023, author={Vaidhyanathan Krishnamurthy, G., Chirumamilla, M., Krekeler, T., Ritter, M., Raudsepp, R., Schieda, M., Klassen, T., Pedersen, K., Petrov, A.Y., Eich, M., Störmer, M.}, title={Iridium based selective emitters for thermophotovoltaic applications}, year={2023}, howpublished = {journal article}, doi = {https://doi.org/10.1002/adma.202305922}, abstract = {The long-term operation of refractory-metal-based metamaterials is crucial for applications such as thermophotovoltaics. The metamaterials based on refractory metals like W, Mo, Ta, Nb, and Re fail primarily by oxidation. Here, the use of the noble metal Ir is proposed, which is stable to oxidation and has optical properties comparable to gold. The thermal endurance of Ir in a 3-layer-system, consisting of HfO2/Ir/HfO2, by performing annealing experiments up to 1240 °C in a pressure range from 2 × 10−6 mbar to 1 bar, is demonstrated. The Ir layer shows no oxidation in a vacuum and inert gas atmosphere. At temperatures above 1100 °C, the Ir layer starts to agglomerate due to the degradation of the confining HfO2 layers. An in situ X-ray diffraction experimental comparison between 1D multilayered Ir/HfO2 and W/HfO2 selective emitters annealed at 1000 °C, 2 × 10−6 mbar, over 100 h, confirms oxidation stability of Ir while W multilayers gradually disappear. The results of this work show that W-based metamaterials are not long-term stable even at 1000 °C. However, the oxidation resistance of Ir can be leveraged for refractory plasmonic metamaterials, such as selective emitters in thermophotovoltaic systems with strong suppression of long wavelength radiation.}, note = {Online available at: \url{https://doi.org/10.1002/adma.202305922} (DOI). Vaidhyanathan Krishnamurthy, G.; Chirumamilla, M.; Krekeler, T.; Ritter, M.; Raudsepp, R.; Schieda, M.; Klassen, T.; Pedersen, K.; Petrov, A.; Eich, M.; Störmer, M.: Iridium based selective emitters for thermophotovoltaic applications. Advanced Materials. 2023. 2305922. DOI: 10.1002/adma.202305922}} @misc{neves_development_of_2023, author={Neves, A.M., Puszkiel, J., Capurso, G., Bellosta von Colbe, J.M., Klassen, T., Jepsen, J.}, title={Development of a new approach for the kinetic modeling of the lithium reactive hydride composite (Li-RHC) for hydrogen storage under desorption conditions}, year={2023}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.cej.2023.142274}, abstract = {Among some promising candidates for high-capacity energy and hydrogen storage is the Lithium-Boron Reactive Hydride Composite System (Li-RHC: 2 LiH + MgB2/2 LiBH4 + MgH2). This system desorbs hydrogen only at relatively high temperatures and presents a two-step series of reactions occurring in different time scales: first, MgH2 desorbs, followed by LiBH4. Hitherto, the dehydrogenation kinetic behavior of such a system has been described for different temperatures at specific values of operative pressure. However, a comprehensive model representing its dehydrogenation kinetic behavior under different operative conditions has not yet been developed. Herein, the separable variable method is applied to develop a comprehensive kinetic model, including the two-step dehydrogenation series reaction. The MgH2 decomposition is described with the one-dimensional interface-controlled reaction rate Johnson-Mehl-Avrami-Erofeyev-Kholmogorov (JMAEK) with a (Pequilibrium/Poperative) pressure functionality and an Arrhenius temperature dependence activation energy of 63 ± 3 kJ/mol H2. The LiBH4 decomposition is modeled applying the autocatalytic Prout-Tompkins model. A novel approach to describe the Prout-Tompkins t0 parameter as a function of the operative temperature and pressure model is proposed. This second reaction step presented a (Pequilibrium – Poperative/Pequilibrium)2 pressure dependence and an Arrhenius temperature dependence with activation energy 94 ± 13 kJ/mol H2. The proposed approach is experimentally and computationally validated, successfully describing the decomposition kinetic behavior of MgH2 and LiBH4 under three-phase gas, liquid and solid environment and shows good agreement between experimental and modeled curves.}, note = {Online available at: \url{https://doi.org/10.1016/j.cej.2023.142274} (DOI). Neves, A.; Puszkiel, J.; Capurso, G.; Bellosta von Colbe, J.; Klassen, T.; Jepsen, J.: Development of a new approach for the kinetic modeling of the lithium reactive hydride composite (Li-RHC) for hydrogen storage under desorption conditions. Chemical Engineering Journal. 2023. vol. 464, 142274. DOI: 10.1016/j.cej.2023.142274}} @misc{taube_h2antrieb_auf_2023, author={Taube, K., Dzaak, V., Mühmer, M.}, title={H2-Antrieb auf der Coriolis}, year={2023}, howpublished = {journal article}, abstract = {Global ist die Schifffahrt für etwa drei Prozent aller Kohlenstoffdioxidemissionen verantwortlich. Die Internationale Seeschifffahrts-Organisation IMO (von engl. International Maritime Organization) hat sich daher zum Ziel gesetzt, diese bis zum Jahr 2050, verglichen mit dem Stand von 2008, mindestens zu halbieren. Für Schiffe werden aufgrund der hohen Leistungsbedarfe und der großen zurückzulegenden Reichweiten vollelektrische Lösungen nur in einigen Anwendungsfällen möglich sein. Wasserstoff und seine Derivate wecken daher bei der maritimen Industrie zunehmendes Interesse aufgrund ihres Potentials, den Emissionsausstoß der Schifffahrt deutlich zu reduzieren. Die Herausforderung ist dabei, Wasserstoff einerseits in sicherer Form und möglichst kompakt an Bord zu speichern und andererseits das Gesamtenergiesystem auf verschiedene Anforderungen abzustimmen und seine Steuerung optimal zu gestalten.}, note = {Taube, K.; Dzaak, V.; Mühmer, M.: H2-Antrieb auf der Coriolis. HZwei - Das Magazin fuer Wasserstoff und Brennstoffzellen. 2023. no. 3, 32-33.}} @misc{santhosh_influence_of_2023, author={Santhosh, A., Kang, S., Keilbart, N., Wood, B.C., Klassen, T., Jerabek, P., Dornheim, M.}, title={Influence of near-surface oxide layers on TiFe hydrogenation - Mechanistic insights and implications for hydrogen storage applications}, year={2023}, howpublished = {journal article}, doi = {https://doi.org/10.1039/D3TA02205F}, abstract = {The inevitable formation of passivating oxide films on the surface of the TiFe intermetallic compound limits its performance as a stationary hydrogen storage material. Extensive experimental efforts have been dedicated to the activation of TiFe, i.e. oxide layer removal prior to utilization for hydrogen storage. However, development of an efficient activation protocol necessitates a fundamental understanding of the composition and structure of the air-exposed surface and its interaction with hydrogen, which is currently absent. Therefore, in this study we explored the growth and nature of oxide films on the most exposed TiFe surface (110) in depth using static and dynamic first-principles methods. We identified the lowest energy structures for six oxygen coverages up to approximately 1.12 nm of thickness with a global optimization method and studied the temperature effects and structural evolution of the oxide phases in detail via ab initio molecular dynamics (AIMD). Based on structural similarity and coordination analysis, motifs for TiO2 and TiFeO3 as well as Ti(FeO2)x (x = 2, 3 or 5) phases were identified. On evaluating the interaction of the oxidized surface with hydrogen, a minimal energy barrier of 0.172 eV was predicted for H2 dissociation while H migration from the top of the oxidized surface to the bulk TiFe was limited by several high-lying energy barriers above 1.4 eV. Our mechanistic insights will prove themselves valuable for informed designs towards new activation methods of TiFe and related systems as hydrogen storage materials.}, note = {Online available at: \url{https://doi.org/10.1039/D3TA02205F} (DOI). Santhosh, A.; Kang, S.; Keilbart, N.; Wood, B.; Klassen, T.; Jerabek, P.; Dornheim, M.: Influence of near-surface oxide layers on TiFe hydrogenation - Mechanistic insights and implications for hydrogen storage applications. Journal of Materials Chemistry A. 2023. vol. 11, 18776-18789. DOI: 10.1039/D3TA02205F}} @misc{wetegrove_preventing_hydrogen_2023, author={Wetegrove, M., Duarte, M.J., Taube, K., Rohloff, M., Gopalan, H., Scheu, C., Dehm, G., Kruth, A.}, title={Preventing Hydrogen Embrittlement: The Role of Barrier Coatings for the Hydrogen Economy}, year={2023}, howpublished = {journal article}, doi = {https://doi.org/10.3390/hydrogen4020022}, abstract = {Hydrogen barrier coatings are protective layers consisting of materials with a low intrinsic hydrogen diffusivity and solubility, showing the potential to delay, reduce or hinder hydrogen permeation. Hydrogen barrier coatings are expected to enable steels, which are susceptible to hydrogen embrittlement, specifically cost-effective low alloy-steels or light-weight high-strength steels, for applications in a hydrogen economy. Predominantly, ceramic coating materials have been investigated for this purpose, including oxides, nitrides and carbides. In this review, the state of the art with respect to hydrogen permeation is discussed for a variety of coatings. Al2O3, TiAlN and TiC appear to be the most promising candidates from a large pool of ceramic materials. Coating methods are compared with respect to their ability to produce layers with suitable quality and their potential for scaling up for industrial use. Different setups for the characterisation of hydrogen permeability are discussed, using both gaseous hydrogen and hydrogen originating from an electrochemical reaction. Finally, possible pathways for improvement and optimisation of hydrogen barrier coatings are outlined.}, note = {Online available at: \url{https://doi.org/10.3390/hydrogen4020022} (DOI). Wetegrove, M.; Duarte, M.; Taube, K.; Rohloff, M.; Gopalan, H.; Scheu, C.; Dehm, G.; Kruth, A.: Preventing Hydrogen Embrittlement: The Role of Barrier Coatings for the Hydrogen Economy. Hydrogen. 2023. vol. 4, no. 2, 307-322. DOI: 10.3390/hydrogen4020022}} @misc{tenholt_design_of_2022, author={Tenholt, C., Höche, D., Schieda, M., Klassen, T.}, title={Design of a reference model for fast optimization of photo-electrochemical cells}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1039/D1SE01671G}, abstract = {In research and development of photo-electrochemical (PEC) cells for water splitting, most results up to now are based on simulations and experiments on laboratory scales. However, to make PEC cells attractive for application, scaling up their size and energy efficiency is necessary. Therefore, we investigate the effects of stepwise upscaling of PEC cells. On the experimental level, cells with metal oxide electrodes of different sizes and shapes as well as cell tank geometries are characterized with respect to their surface reactions and photo-current output. In order to predict their behavior on different scales, a computer-aided reference model is developed simultaneously. This is benchmarked by testing various cell sizes and shapes, enabled by fast and cost-efficient fabrication via 3D printing. Machine learning via Bayesian optimization was employed to optimize the PEC cell simulation model input parameters, resulting in very good agreement within a few percent of computed and measured current–voltage curves with Pt-electrodes. Transferring these input parameters to the same cell geometry but with a semiconductor anode, deviations of less than 25% were observed. Here, we present experimental results of the PEC cells, as well as the first drafts of the simulation model and the optimization approach.}, note = {Online available at: \url{https://doi.org/10.1039/D1SE01671G} (DOI). Tenholt, C.; Höche, D.; Schieda, M.; Klassen, T.: Design of a reference model for fast optimization of photo-electrochemical cells. Sustainable Energy and Fuels. 2022. vol. 6, no. 6, 1489-1498. DOI: 10.1039/D1SE01671G}} @misc{bozheyev_transient_surface_2022, author={Bozheyev, F., Fengler, S., Kollmann, J., Klassen, T., Schieda, M.}, title={Transient Surface Photovoltage Spectroscopy of (NH4)2Mo3S13/WSe2 Thin-Film Photocathodes for Photoelectrochemical Hydrogen Evolution}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acsami.2c01623}, abstract = {Hydrogen produced from solar energy has the potential to replace petroleum in the future. To this respect, there is a need in the abandoned and efficient materials that can continuously split water molecules using solar energy. In this report, an ammonium thiomolybdate (ATM: (NH4)2Mo3S13) is evaluated as a p-type semiconductor film photocathode for hydrogen evolution reaction. The ATM thin films are prepared by spin-coating on fluorine-doped tin oxide substrates, and their structural, morphological, optical, photoelectrical, and photoelectrochemical (PEC) properties are studied. Transient surface photovoltage (TSPV) spectroscopy and spectroscopic ellipsometry indicate the band gap Eg = 1.9 eV for the ATM thin films. Furthermore, the photovoltage of the ATM thin films measured by TSPV is correlated to the photocurrents measured by the PEC characterization that can be used to evaluate the material potential for hydrogen generation. The films exhibit a low photocurrent density of 46 μA cm–2 at 0 VRHE. However, its combination with WSe2 thin-film photocathodes results in a significant increase in photocurrent density up to 4.6 mA cm–2 at 0 VRHE (100 times). The reason for such a strong charge carrier transfer effect for ATM/WSe2 heterojunction photocathodes is studied by TSPV spectroscopy that allows a comprehensive evaluation of potential photovoltaic materials toward PEC hydrogen production. Furthermore, the photovoltage generated by a WSe2 thin film is 30 times lower than that of its single crystal, which indicates that the quality of WSe2 thin films should be improved for faster PEC hydrogen evolution.}, note = {Online available at: \url{https://doi.org/10.1021/acsami.2c01623} (DOI). Bozheyev, F.; Fengler, S.; Kollmann, J.; Klassen, T.; Schieda, M.: Transient Surface Photovoltage Spectroscopy of (NH4)2Mo3S13/WSe2 Thin-Film Photocathodes for Photoelectrochemical Hydrogen Evolution. ACS Applied Materials and Interfaces. 2022. vol. 14, no. 19, 22071-22081. DOI: 10.1021/acsami.2c01623}} @misc{alvares_modeling_the_2022, author={Alvares, E., Jerabek, P., Shang, Y., Santhosh, A., Pistidda, C., Heo, T., Sundman, B., Dornheim, M.}, title={Modeling the thermodynamics of the FeTi hydrogenation under para-equilibrium: An ab-initio and experimental study}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.calphad.2022.102426}, abstract = {FeTi-based hydrides have recently re-attracted attention as stationary hydrogen storage materials due to favorable reversibility, good sorption kinetics and relatively low costs compared to alternative intermetallic hydrides. Employing the OpenCalphad software, the thermodynamics of the (FeTi)H (0 1) system were assessed as a key basis for modeling hydrogenation of FeTi-based alloys. New thermodynamic data were acquired from our experimental pressure-composition-isotherm (PCI) curves, as well as first-principles calculations utilizing density functional theory (DFT). The thermodynamic phase models were carefully selected based on critical analysis of literature information and ab-initio investigations. Key thermodynamic properties such as dissociation pressure, formation enthalpies and phase diagrams were calculated in good agreement to our performed experiments and literature-reported data. This work provides an initial perspective, which can be extended to account for higher-order thermodynamic assessments and subsequently enables the design of novel FeTi-based hydrides. In addition, the assessed thermodynamic data can serve as key inputs for kinetic models and hydride microstructure simulations.}, note = {Online available at: \url{https://doi.org/10.1016/j.calphad.2022.102426} (DOI). Alvares, E.; Jerabek, P.; Shang, Y.; Santhosh, A.; Pistidda, C.; Heo, T.; Sundman, B.; Dornheim, M.: Modeling the thermodynamics of the FeTi hydrogenation under para-equilibrium: An ab-initio and experimental study. Calphad. 2022. vol. 77, 102426. DOI: 10.1016/j.calphad.2022.102426}} @misc{bondi_quantitative_assessment_2022, author={Bondi, L., Garden, A., Totti, F., Jerabek, P., Brooker, S.}, title={Quantitative Assessment of Ligand Substituent Effects on σ- and π-Contributions to Fe−N Bonds in Spin Crossover FeII Complexes}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1002/chem.202104314}, abstract = {T1/2 values in this family of complexes, consistent with the calculated MO energy levels, that M→L π-backdonation dominates in these M−L bonds. Here the quantitative EDA-NOCV analysis of the M−L bond contributions provides a more complete, coherent and detailed picture of the relative impact of M−L σ-versus π-bonding in determining the observed T1/2, refining the earlier interpretation and revealing the importance of the σ-bonding. Furthermore, our results are in perfect agreement with the ΔE(HS-LS) vs. σp+(X) correlation reported in their work.}, note = {Online available at: \url{https://doi.org/10.1002/chem.202104314} (DOI). Bondi, L.; Garden, A.; Totti, F.; Jerabek, P.; Brooker, S.: Quantitative Assessment of Ligand Substituent Effects on σ- and π-Contributions to Fe−N Bonds in Spin Crossover FeII Complexes. Chemistry - A European Journal. 2022. vol. 28, no. 22, e202104314. DOI: 10.1002/chem.202104314}} @misc{huang_tailoring_powder_2022, author={Huang, C., List, A., Shen, J., Fu, B., Yin, S., Chen, T., Klusemann, B., Gärtner, F., Klassen, T.}, title={Tailoring powder strengths for enhanced quality of cold sprayed Al6061 deposits}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.matdesdx..2022.110494}, abstract = {As verified by literature, heat-treatments of as-atomized Al-alloy powders before cold spraying, result in microstructural homogenization and deposition efficiency increment. So far, a straightforward correlation between powder strength and consequences for the performance in cold spraying and deposit properties is still missing. This work thus provides reliable analyses of powder strengths in as-atomized and annealed states to the calculation of critical velocities and deposit quality parameter η, as well as the associated influences of powder strength on single-particle adhesion and deposit microstructures and properties. By annealing of as-atomized powder, its strength is reduced by about 60%, which allows decreasing the critical velocity for a successful deposition. Experimental results demonstrate that powder strength-based calculation of quality parameter η allows for a more realistic description of microstructural characteristics and deposits properties. The single-particle impact morphologies as well as the detachment features of adhering splats by cavitation tests visualize the respective deposition characteristics and bonding behaviors. The lower critical velocities by annealing contribute to better single splat adhesion, lower porosity, higher electrical conductivity, as well as improved tensile strength of deposits. The direct correlation of powder pre-annealing and strength in combination with cold spraying parameter variation allows defining effective strategies for improving deposit properties.}, note = {Online available at: \url{https://doi.org/10.1016/j.matdesdx..2022.110494} (DOI). Huang, C.; List, A.; Shen, J.; Fu, B.; Yin, S.; Chen, T.; Klusemann, B.; Gärtner, F.; Klassen, T.: Tailoring powder strengths for enhanced quality of cold sprayed Al6061 deposits. Materials & Design. 2022. vol. 215, 110494. DOI: 10.1016/j.matdesdx..2022.110494}} @misc{gizer_effect_of_2022, author={Gizer, G., Karimi, F., Pistidda, C., Cao, H., Puszkiel, J., Shang, Y., Gericke, E., Hoell, A., Pranzas, K., Klassen, T., Dornheim, M.}, title={Effect of the particle size evolution on the hydrogen storage performance of KH doped Mg(NH2)2 + 2LiH}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s10853-022-06985-4}, abstract = {In recent years, many solid-state hydride-based materials have been considered as hydrogen storage systems for mobile and stationary applications. Due to a gravimetric hydrogen capacity of 5.6 wt% and a dehydrogenation enthalpy of 38.9 kJ/mol H2, Mg(NH2)2 + 2LiH is considered a potential hydrogen storage material for solid-state storage systems to be coupled with PEM fuel cell devices. One of the main challenges is the reduction of dehydrogenation temperature since this system requires high dehydrogenation temperatures (~ 200 °C). The addition of KH to this system significantly decreases the dehydrogenation onset temperature to 130 °C. On the one hand, the addition of KH stabilizes the hydrogen storage capacity. On the other hand, the capacity is reduced by 50% (from 4.1 to 2%) after the first 25 cycles. In this work, the particle sizes of the overall hydride matrix and the potassium-containing species are investigated during hydrogen cycling. Relation between particle size evolution of the additive and hydrogen storage kinetics is described by using an advanced synchrotron-based technique: Anomalous small-angle X-ray scattering, which was applied for the first time at the potassium K-edge for amide-hydride hydrogen storage systems. The outcomes from this investigation show that, the nanometric potassium-containing phases might be located at the reaction interfaces, limiting the particle coarsening. Average diameters of potassium-containing nanoparticles double after 25 cycles (from 10 to 20 nm). Therefore, reaction kinetics at subsequent cycles degrade. The deterioration of the reaction kinetics can be minimized by selecting lower absorption temperatures, which mitigates the particle size growth, resulting in two times faster reaction kinetics.}, note = {Online available at: \url{https://doi.org/10.1007/s10853-022-06985-4} (DOI). Gizer, G.; Karimi, F.; Pistidda, C.; Cao, H.; Puszkiel, J.; Shang, Y.; Gericke, E.; Hoell, A.; Pranzas, K.; Klassen, T.; Dornheim, M.: Effect of the particle size evolution on the hydrogen storage performance of KH doped Mg(NH2)2 + 2LiH. Journal of Materials Science. 2022. vol. 57, no. 22, 10028-10038. DOI: 10.1007/s10853-022-06985-4}} @misc{cao_dehydrogenationrehydrogenation_properties_2022, author={Cao, H., Pistidda, C., Richter, T.M.M., Capurso, G., Milanese, C., Tseng, J.-C., Shang, Y., Niewa, R., Chen, P., Klassen, T., Dornheim, M.}, title={De-hydrogenation/Rehydrogenation Properties and Reaction Mechanism of AmZn(NH2)n-2nLiH Systems (A = Li, K, Na, and Rb)}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.3390/su14031672}, abstract = {With the aim to find suitable hydrogen storage materials for stationary and mobile applications, multi-cation amide-based systems have attracted considerable attention, due to their unique hydrogenation kinetics. In this work, AmZn(NH2)n (with A = Li, K, Na, and Rb) were synthesized via an ammonothermal method. The synthesized phases were mixed via ball milling with LiH to form the systems AmZn(NH2)n-2nLiH (with m = 2, 4 and n = 4, 6), as well as Na2Zn(NH2)4∙0.5NH3-8LiH. The hydrogen storage properties of the obtained materials were investigated via a combination of calorimetric, spectroscopic, and diffraction methods. As a result of the performed analyses, Rb2Zn(NH2)4-8LiH appears as the most appealing system. This composite, after de-hydrogenation, can be fully rehydrogenated within 30 s at a temperature between 190 °C and 200 °C under a pressure of 50 bar of hydrogen.}, note = {Online available at: \url{https://doi.org/10.3390/su14031672} (DOI). Cao, H.; Pistidda, C.; Richter, T.; Capurso, G.; Milanese, C.; Tseng, J.; Shang, Y.; Niewa, R.; Chen, P.; Klassen, T.; Dornheim, M.: De-hydrogenation/Rehydrogenation Properties and Reaction Mechanism of AmZn(NH2)n-2nLiH Systems (A = Li, K, Na, and Rb). Sustainability. 2022. vol. 14, no. 3, 1672. DOI: 10.3390/su14031672}} @misc{passing_development_and_2022, author={Passing, M., Pistidda, C., Capurso, G., Jepsen, J., Metz, O., Dornheim, M., Klassen, T.}, title={Development and experimental validation of kinetic models for the hydrogenation/dehydrogenation of Mg/Al based metal waste for energy storage}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jma.2021.12.005}, abstract = {With the increased use of renewable energy sources, the need to store large amounts of energy will become increasingly important in the near future. A cost efficient possibility is to use the reaction of recycled Mg waste with hydrogen as thermo-chemical energy storage. Owing to the high reaction enthalpy, the moderate pressure and appropriate temperature conditions, the broad abundance and the recyclability, the Mg/Al alloy is perfectly suitable for this purpose. As further development of a previous work, in which the performance of recycled Mg/Al waste was presented, a kinetic model for hydro- and dehydrogenation is derived in this study. Temperature and pressure dependencies are determined, as well as the rate limiting step of the reaction. First experiments are carried out in an autoclave with a scaled-up powder mass, which is also used to validate the model by simulating the geometry with the scaled-up experiments at different conditions.}, note = {Online available at: \url{https://doi.org/10.1016/j.jma.2021.12.005} (DOI). Passing, M.; Pistidda, C.; Capurso, G.; Jepsen, J.; Metz, O.; Dornheim, M.; Klassen, T.: Development and experimental validation of kinetic models for the hydrogenation/dehydrogenation of Mg/Al based metal waste for energy storage. Journal of Magnesium and Alloys. 2022. vol. 10, no. 10, 2761-2774. DOI: 10.1016/j.jma.2021.12.005}} @misc{dreistadt_a_novel_2022, author={Dreistadt, D.M., Puszkiel, J., von Colbe, J.M.B., Capurso, G., Steinebach, G., Meilinger, S., Le, T.-T., Guarneros, M.C., Klassen, T., Jepsen, J.}, title={A Novel Emergency Gas-to-Power System Based on an Efficient and Long-Lasting Solid-State Hydride Storage System: Modeling and Experimental Validation}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.3390/en15030844}, abstract = {In this paper, a gas-to-power (GtoP) system for power outages is digitally modeled and experimentally developed. The design includes a solid-state hydrogen storage system composed of TiFeMn as a hydride forming alloy (6.7 kg of alloy in five tanks) and an air-cooled fuel cell (maximum power: 1.6 kW). The hydrogen storage system is charged under room temperature and 40 bar of hydrogen pressure, reaching about 110 g of hydrogen capacity. In an emergency use case of the system, hydrogen is supplied to the fuel cell, and the waste heat coming from the exhaust air of the fuel cell is used for the endothermic dehydrogenation reaction of the metal hydride. This GtoP system demonstrates fast, stable, and reliable responses, providing from 149 W to 596 W under different constant as well as dynamic conditions. A comprehensive and novel simulation approach based on a network model is also applied. The developed model is validated under static and dynamic power load scenarios, demonstrating excellent agreement with the experimental results.}, note = {Online available at: \url{https://doi.org/10.3390/en15030844} (DOI). Dreistadt, D.; Puszkiel, J.; von Colbe, J.; Capurso, G.; Steinebach, G.; Meilinger, S.; Le, T.; Guarneros, M.; Klassen, T.; Jepsen, J.: A Novel Emergency Gas-to-Power System Based on an Efficient and Long-Lasting Solid-State Hydride Storage System: Modeling and Experimental Validation. Energies. 2022. vol. 15, no. 3, 844. DOI: 10.3390/en15030844}} @misc{abetz_reactive_hydride_2022, author={Abetz, C., Georgopanos, P., Pistidda, C., Klassen, T., Abetz, V.}, title={Reactive Hydride Composite Confined in a Polymer Matrix: New Insights into the Desorption and Absorption of Hydrogen in a Storage Material with High Cycling Stability}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1002/admt.202101584}, abstract = {Hydrogen is key to the transformation of today's energy technology toward a sustainable future without carbon dioxide emissions. Hydrogen can be produced from water using renewable or sustainable energy sources such as solar or wind power. It can buffer fluctuations between energy generation and use in all energy sectors, stationary heat, and power, as well as mobility. Safe, fast, and easy to handle solutions for storing and releasing hydrogen are essential for the implementation of hydrogen technology. Among the storage alternatives, metal hydride materials represent a safe and efficient option. For the first time, detailed investigations of the local chemical changes in a confined hydrogen storage material before and after 21 hydrogen-unloading and loading cycles are reported. The system is based on micrometer-sized reactive hydride composite (RHC) particles, namely 6Mg(NH2)2 + 9LiH + 1LiBH4, dispersed in a matrix of poly(4-methyl-1-pentene) (TPXTM). The morphological stability of the confined RHC particles during the reversible and almost complete reaction with hydrogen is visualized in detail, explaining the excellent long-term cycling stability.}, note = {Online available at: \url{https://doi.org/10.1002/admt.202101584} (DOI). Abetz, C.; Georgopanos, P.; Pistidda, C.; Klassen, T.; Abetz, V.: Reactive Hydride Composite Confined in a Polymer Matrix: New Insights into the Desorption and Absorption of Hydrogen in a Storage Material with High Cycling Stability. Advanced Materials Technologies. 2022. vol. 7, no. 11, 2101584. DOI: 10.1002/admt.202101584}} @misc{dreistadt_an_effective_2022, author={Dreistadt, D., Le, T., Capurso, G., Bellosta von Colbe, J., Santhosh, A., Pistidda, C., Scharnagl, N., Ovri, H., Milanese, C., Jerabek, P., Klassen, T., Jepsen, J.}, title={An effective activation method for industrially produced TiFeMn powder for hydrogen storage}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2022.165847}, abstract = {This work proposes an effective thermal activation method with low technical effort for industrially produced titanium-iron-manganese powders (TiFeMn) for hydrogen storage. In this context, the influence of temperature and particle size of TiFeMn on the activation process is systematically studied. The results obtained from this investigation suggest that the activation of the TiFeMn material at temperatures as low as 50 °C is already possible, with a combination of “Dynamic” and “Static” routines, and that an increase to 90 °C strongly reduces the incubation time for activation, i.e. the incubation time of the sample with the two routines at 90 °C is about 0.84 h, while ∼ 277 h is required for the sample treated at 50 °C in both “Dynamic” and “Static” sequences. Selecting TiFeMn particles of larger size also leads to significant improvements in the activation performance of the investigated material. The proposed activation routine makes it possible to overcome the oxide layer existing on the compound surface, which acts as a diffusion barrier for the hydrogen atoms. This activation method induces further cracks and defects in the powder granules, generating new surfaces for hydrogen absorption with greater frequency, and thus leading to faster sorption kinetics in the subsequent absorption-desorption cycles.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2022.165847} (DOI). Dreistadt, D.; Le, T.; Capurso, G.; Bellosta von Colbe, J.; Santhosh, A.; Pistidda, C.; Scharnagl, N.; Ovri, H.; Milanese, C.; Jerabek, P.; Klassen, T.; Jepsen, J.: An effective activation method for industrially produced TiFeMn powder for hydrogen storage. Journal of Alloys and Compounds. 2022. vol. 919, 165847. DOI: 10.1016/j.jallcom.2022.165847}} @misc{hariyadi_modeling_of_2022, author={Hariyadi, A., Suwarno, S., Denys, R., Bellosta von Colbe, J., Saetre, T., Yartys, V.}, title={Modeling of the hydrogen sorption kinetics in an AB2 laves type metal hydride alloy}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2021.162135}, abstract = {Hydrides of the AB2 Laves type alloys (A=Zr, Ti; B = transition metal – Fe, Co, Ni, Mn, Cr, V) have been extensively studied as materials for the storage of gaseous hydrogen. They contain up to 4 H atoms/formula unit AB2, thus achieving reversible H storage capacities in the range between 1.5 and 2.0 wt% H and offering high rates of hydrogen charge and discharge, thus making them suitable for designing efficient hydrogen stores operating at ambient conditions. In the present study, we performed an experimental study and modeling of the thermodynamics and the kinetics of interaction in the AB2-hydrogen system. The experimental data was collected by studying a model alloy with a composition Ti0.15Zr0.85La0.03Ni1.126Mn0.657V0.113Fe0.113. Hydrogen absorption and desorption were studied in a volumetric Sieverts type apparatus at isothermal conditions using a single-step change/discharge and stepwise methods. The results obtained from the model simulation show that the reaction follows the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model, with the value of exponent n = 1–1.25 for absorption and 1 for desorption. This indicates that the rate-limiting hydrogen absorption and desorption steps are jointly governed by hydrogen diffusion and grain boundary nucleation of alpha-solid solution and beta-hydride. The activation energies for both hydrogen absorption and desorption decrease along with increasing hydrogen content in the hydride.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2021.162135} (DOI). Hariyadi, A.; Suwarno, S.; Denys, R.; Bellosta von Colbe, J.; Saetre, T.; Yartys, V.: Modeling of the hydrogen sorption kinetics in an AB2 laves type metal hydride alloy. Journal of Alloys and Compounds. 2022. vol. 893, 162135. DOI: 10.1016/j.jallcom.2021.162135}} @misc{daneshian_features_of_2022, author={Daneshian, B., Gärtner, F., Assadi, H., Vidaller, M., Höche, D., Klassen, T.}, title={Features of ceramic nanoparticle deformation in aerosol deposition explored by molecular dynamics simulation}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.surfcoat.2021.127886}, abstract = {The deformation and bonding of particles in Aerosol Deposition (AD) is a topic of growing technological interest for solid-state coating and additive manufacturing with ceramic materials. The core feature of the AD process is the unexpected plasticity of ceramics at high strain rates and small length scales, which is also a topic of general interest for understanding the response of intrinsically brittle materials to dynamic deformation. We explore this feature through computational analysis of the impact of ceramic particles – modelled based on a Lennard-Jones description of submicron TiO2-anatase particles in a two-dimensional molecular-dynamics system – onto a substrate at a range of impact velocities (100–800 m/s). The deformation behaviour of the particle for each impact velocity was analysed with respect to the evolution of the stress, strain, and temperature fields. The results reveal indications of dislocation-based plasticity within a certain velocity regime. This velocity regime, which becomes narrower with increasing the particle size, coincides incidentally with bonding of particles to the substrate in AD. The results also show that outside this regime, the impact is associated predominantly with either rebounding (at lower velocities) or particle fracture (at higher velocities). The simulation results are interpreted in view of a phenomenological model of fragmentation, considering the interplay between the material properties, such as the fracture energy, and the kinetic energy of particles upon impact. Based on the simulations and the analytical model, a window of deposition is proposed for AD.}, note = {Online available at: \url{https://doi.org/10.1016/j.surfcoat.2021.127886} (DOI). Daneshian, B.; Gärtner, F.; Assadi, H.; Vidaller, M.; Höche, D.; Klassen, T.: Features of ceramic nanoparticle deformation in aerosol deposition explored by molecular dynamics simulation. Surface and Coatings Technology. 2022. vol. 429, 127886. DOI: 10.1016/j.surfcoat.2021.127886}} @misc{shang_sustainable_naalh4_2022, author={Shang, Y., Pistidda, C., Milanese, C., Girella, A., Schökel, A., Le, T., Hagenah, A., Metz, O., Klassen, T., Dornheim, M.}, title={Sustainable NaAlH4 production from recycled automotive Al alloy}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1039/D1GC04709D}, abstract = {To reduce the carbon footprint associated with the production of hydrogen storage materials and to reduce their cost, we pursue the possibility of obtaining high-quality hydride-based materials from industrial metals waste. In particular, in this manuscript, we propose a method for obtaining high-quality NaAlH4, starting from the Al-based automotive recycled alloy DIN-GDAlSi10Mg(Cu). The hydrogen storage properties of the material obtained by ball milling NaH and DIN-GDAlSi10Mg(Cu) under a hydrogen atmosphere were comprehensively explored via a broad range of experimental techniques, e.g. volumetric analysis, ex situ X-ray diffraction (XRD), in situ synchrotron radiation powder X-ray diffraction (SR-PXD), scanning electron microscopy (SEM), and differential thermal analysis (DTA). These investigations show that NaAlH4 was successfully synthesized and that its properties are comparable with those of high-purity commercial NaAlH4.}, note = {Online available at: \url{https://doi.org/10.1039/D1GC04709D} (DOI). Shang, Y.; Pistidda, C.; Milanese, C.; Girella, A.; Schökel, A.; Le, T.; Hagenah, A.; Metz, O.; Klassen, T.; Dornheim, M.: Sustainable NaAlH4 production from recycled automotive Al alloy. Green Chemistry. 2022. vol. 24, no. 10, 4153-4163. DOI: 10.1039/D1GC04709D}} @misc{mengisn_netzero_co2_2022, author={Mengis N., Kalhori A., Simon S., Harpprecht C., Baetcke L., Prats-Salvado E., Schmidt-Hattenberger C., Stevenson A., Dold C., El Zohbi J., Borchers M., Thrän D., Korte K., Gawel E., Dolch T., Heß D., Yeates C., Thoni T., Markus T., Schill E., Xiao M., Köhnke F., Oschlies A., Förster J., Görl K., Dornheim M., Brinkmann T., Beck S., Bruhn D., Li Z., Steuri B., Herbst M., Sachs T., Monnerie N., Pregger T., Jacob D., Dittmeyer R.}, title={Net-Zero CO2 Germany - A Retrospect From the Year 2050}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1029/2021EF002324}, abstract = {Germany 2050: For the first time Germany reached a balance between its sources of anthropogenic CO2 to the atmosphere and newly created anthropogenic sinks. This backcasting study presents a fictional future in which this goal was achieved by avoiding (∼645 Mt CO2), reducing (∼50 Mt CO2) and removing (∼60 Mt CO2) carbon emissions. This meant substantial transformation of the energy system, increasing energy efficiency, sector coupling, and electrification, energy storage solutions including synthetic energy carriers, sector-specific solutions for industry, transport, and agriculture, as well as natural-sink enhancement and technological carbon dioxide options. All of the above was necessary to achieve a net-zero CO2 system for Germany by 2050.}, note = {Online available at: \url{https://doi.org/10.1029/2021EF002324} (DOI). Mengis N.; Kalhori A.; Simon S.; Harpprecht C.; Baetcke L.; Prats-Salvado E.; Schmidt-Hattenberger C.; Stevenson A.; Dold C.; El Zohbi J.; Borchers M.; Thrän D.; Korte K.; Gawel E.; Dolch T.; Heß D.; Yeates C.; Thoni T.; Markus T.; Schill E.; Xiao M.; Köhnke F.; Oschlies A.; Förster J.; Görl K.; Dornheim M.; Brinkmann T.; Beck S.; Bruhn D.; Li Z.; Steuri B.; Herbst M.; Sachs T.; Monnerie N.; Pregger T.; Jacob D.; Dittmeyer R.: Net-Zero CO2 Germany - A Retrospect From the Year 2050. Earth’s Future. 2022. vol. 10, no. 2, e2021EF002324. DOI: 10.1029/2021EF002324}} @misc{fogel_sng_based_2022, author={Fogel, S., Yeates, C., Unger, S., Rodriguez-Garcia, G., Baetcke, L., Dornheim, M., Schmidt-Hattenberger, C., Bruhn, D., Hampel, U.}, title={SNG based energy storage systems with subsurface CO2 storage}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1039/D1YA00035G}, abstract = {Large-scale energy storage plants based on power-to-gas-to-power (PtG–GtP) technologies incorporating high temperature electrolysis, catalytic methanation for the provision of synthetic natural gas (SNG) and novel, highly efficient SNG-fired Allam reconversion cycles allow for a confined and circular use of CO2/CH4 and thus an emission-free storage of intermittent renewable energy. This study features a thorough technology assessment for large-scale PtG–GtP storage plants based on highly efficient sCO2 power cycles combined with subsurface CO2 storage. The Allam cycle employs supercritical CO2 as working fluid as well as an oxy-combustion process to reach high efficiencies of up to 66%. The entire PtG–GtP process chain assessed in this study is expected to reach maximum roundtrip efficiencies of 54.2% (with dedicated and sufficient O2 storage) or 49.0% (with a dedicated air separation unit). The implementation of said energy storage systems into existing national energy grids will pose a major challenge, since they will require far-reaching infrastructural changes to the respective systems, such as extensive installations of renewable generation and electrolysis capacities as well as sufficient subsurface storage capacities for both CO2 and CH4. Therefore, this study incorporates an assessment of the present subsurface storage potential for CO2 and CH4 in Germany. Furthermore, a basic forecast study for the German energy system with an assumed mass deployment of the proposed SNG-based PtG–GtP energy storage system for the year 2050 is conducted. In case of a fully circular use of CO2/CH4, when electricity is solely generated by renewable energy sources, 736 GW of renewables, 234 GW of electrolysis and 62 GW of gas-to-power capacities are required in the best case scenario in 2050. The total storage volume on the national scale of Germany for both CO2 and CH4 was determined to be 7.8 billion N m3, respectively, leading to a CH4 storage capacity of 54.5 TW h. The presented investigations illustrate the feasibility of large-scale energy storage systems for renewable electricity based on high temperature electrolysis, catalytic methanation and Allam power cycles paired with large subsurface storages for CO2 and CH4.}, note = {Online available at: \url{https://doi.org/10.1039/D1YA00035G} (DOI). Fogel, S.; Yeates, C.; Unger, S.; Rodriguez-Garcia, G.; Baetcke, L.; Dornheim, M.; Schmidt-Hattenberger, C.; Bruhn, D.; Hampel, U.: SNG based energy storage systems with subsurface CO2 storage. Energy Advances. 2022. vol. 1, 402-421. DOI: 10.1039/D1YA00035G}} @misc{barale_tife085mn005_alloy_2022, author={Barale, J., Dematteis, E., Capurso, G., Neuman, B., Deledda, S., Rizzi, P., Cuevas, F., Baricco, M.}, title={TiFe0.85Mn0.05 alloy produced at industrial level for a hydrogen storage plant}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2022.06.295}, abstract = {Moving from basic research to the implementation of hydrogen storage system based on metal hydride, the industrial production of the active material is fundamental. The alloy TiFe0.85Mn0.05 was selected as H2-carrier for a storage plant of about 50 kg of H2. In this work, a batch of 5 kg of TiFe0.85Mn0.05 alloy was synthesized at industrial level and characterized to determine the structure and phase abundance. The H2 sorption properties were investigated, performing studies on long-term cycling study and resistance to poisoning. The alloy absorbs and desorbs hydrogen between 25 bar and 1 bar at 55 °C, storing 1.0H2 wt.%, displaying fast kinetic, good resistance to gas impurities, and storage stability over 250 cycles. The industrial production promotes the formation of a passive layer and a high amount of secondary phases, observing differences in the H2 sorption behaviour compared to samples prepared at laboratory scale. This work highlights how hydrogen sorption properties of metal hydrides are strictly related to the synthesis method.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2022.06.295} (DOI). Barale, J.; Dematteis, E.; Capurso, G.; Neuman, B.; Deledda, S.; Rizzi, P.; Cuevas, F.; Baricco, M.: TiFe0.85Mn0.05 alloy produced at industrial level for a hydrogen storage plant. International Journal of Hydrogen Energy. 2022. vol. 47, no. 69, 29866-29880. DOI: 10.1016/j.ijhydene.2022.06.295}} @misc{shang_developing_sustainable_2022, author={Shang, Y., Liu, S., Liang, Z., Pyczak, F., Lei, Z., Heidenreich, T., Schökel, A., Kai, J.-J., Gizer, G., Dornheim, M., Klassen, T., Pistidda, C.}, title={Developing sustainable FeTi alloys for hydrogen storage by recycling}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1038/s43246-022-00324-5}, abstract = {Intermetallic alloys such as FeTi have attracted ever-growing attention as a safe and efficient hydrogen storage medium. However, the utilization of high-purity metals for the synthesis of such materials poses considerable concerns over the environmental sustainability of their large-scale production. Here, we report an approach for synthesizing FeTi from industrial scraps of iron (steels C45 and 316 L) and titanium (Ti alloy Grade 2) to reduce the carbon footprint associated with FeTi alloy synthesis, without compromising their hydrogen storage properties. At 50 °C and a pressure of 0 to 100 bar, the alloys obtained by using C45-Ti Grade 2 and 316L-Ti Grade 2 can absorb a maximum amount of hydrogen of 1.61 wt.% and 1.50 wt.%, respectively. Moreover, depending on the type of steel utilized, the thermodynamic properties can be modified. Our findings pave a pathway for developing high-performance, environmentally-sustainable FeTi alloys for hydrogen storage purposes using industrial metal wastes.}, note = {Online available at: \url{https://doi.org/10.1038/s43246-022-00324-5} (DOI). Shang, Y.; Liu, S.; Liang, Z.; Pyczak, F.; Lei, Z.; Heidenreich, T.; Schökel, A.; Kai, J.; Gizer, G.; Dornheim, M.; Klassen, T.; Pistidda, C.: Developing sustainable FeTi alloys for hydrogen storage by recycling. Communications Materials. 2022. vol. 3, no. 1, 101. DOI: 10.1038/s43246-022-00324-5}} @misc{jerabek_solving_a_2022, author={Jerabek, P., Burrows, A., Schwerdtfeger, P.}, title={Solving a problem with a single parameter: a smooth bcc to fcc phase transition for metallic lithium}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1039/D2CC04928G}, abstract = {Density functional calculations for metallic lithium along a cuboidal bcc-to-fcc transformation path demonstrate that the bcc phase is quasi-degenerate with the fcc phase with a very small activiation barrier of 0.1 kJ mol−1, but becomes the dominant phase at higher temperatures in accordance with Landau theory. This resolves the long-standing controversy about the two phases for lithium.}, note = {Online available at: \url{https://doi.org/10.1039/D2CC04928G} (DOI). Jerabek, P.; Burrows, A.; Schwerdtfeger, P.: Solving a problem with a single parameter: a smooth bcc to fcc phase transition for metallic lithium. Chemical Communications : ChemComm. 2022. vol. 58, no. 96, 13369-13372. DOI: 10.1039/D2CC04928G}} @misc{jin_microstructural_study_2022, author={Jin, O., Shang, Y., Huang, X., Mu, X., Szabó, D.V., Le, T.T., Wagner, S., Kübel, C., Pistidda, C., Pundt, A.}, title={Microstructural Study of MgB2 in the LiBH4-MgH2 Composite by Using TEM}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.3390/nano12111893}, abstract = {The hampered kinetics of reactive hydride composites (RHCs) in hydrogen storage and release, which limits their use for extensive applications in hydrogen storage S1and energy conversion, can be improved using additives. However, the mechanism of the kinetic restriction and the additive effect on promoting the kinetics have remained unclear. These uncertainties are addressed by utilizing versatile transmission electron microscopy (TEM) on the LiBH4-MgH2 composite under the influence of the 3TiCl3·AlCl3 additives. The formation of the MgB2 phase, as the rate-limiting step, is emphatically studied. According to the observations, the heterogeneous nucleation of MgB2 relies on different nucleation centers (Mg or TiB2 and AlB2). The varied nucleation and growth of MgB2 are related to the in-plane strain energy density at the interface, resulting from the atomic misfit between MgB2 and its nucleation centers. This leads to distinct MgB2 morphologies (bars and platelets) and different performances in the dehydrogenation kinetics of LiBH4-MgH2. It was found that the formation of numerous MgB2 platelets is regarded as the origin of the kinetic improvement. Therefore, to promote dehydrogenation kinetics in comparable RHC systems for hydrogen storage, it is suggested to select additives delivering a small atomic misfit. View Full-Text}, note = {Online available at: \url{https://doi.org/10.3390/nano12111893} (DOI). Jin, O.; Shang, Y.; Huang, X.; Mu, X.; Szabó, D.; Le, T.; Wagner, S.; Kübel, C.; Pistidda, C.; Pundt, A.: Microstructural Study of MgB2 in the LiBH4-MgH2 Composite by Using TEM. Nanomaterials. 2022. vol. 12, no. 11, 1893. DOI: 10.3390/nano12111893}} @misc{dematteis_hydrogen_storage_2022, author={Dematteis, E.M., Amdisen, M.B., Autrey, T., Barale, J., Bowden, M.E., Buckley, C.E., Cho, Y.W., Deledda, S., Dornheim, M., De Jongh, P., Grinderslev, J.B., Gizer, G., Gulino, V., Hauback, B.C., Heere, M., Heo, T.W., Humphries, T.D., Jensen, T.R., Kang, S.Y., Lee, Y.-S., Li, H.-W., Li, S., Møller, K.T., Ngene, P., Orimo, S.-I., Paskevicius, M., Polanski, M., Takagi, S., Wan, L., Wood, B.C., Hirscher, M., Baricco, M.}, title={Hydrogen storage in complex hydrides: past activities and new trends}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1088/2516-1083/ac7499}, abstract = {Intense literature and research efforts have focussed on the exploration of complex hydrides for energy storage applications over the past decades. A focus was dedicated to the determination of their thermodynamic and hydrogen storage properties, due to their high gravimetric and volumetric hydrogen storage capacities, but their application has been limited because of harsh working conditions for reversible hydrogen release and uptake. The present review aims at appraising the recent advances on different complex hydride systems, coming from the proficient collaborative activities in the past years from the research groups led by the experts of the Task 40 'Energy Storage and Conversion Based on Hydrogen' of the Hydrogen Technology Collaboration Programme of the International Energy Agency. An overview of materials design, synthesis, tailoring and modelling approaches, hydrogen release and uptake mechanisms and thermodynamic aspects are reviewed to define new trends and suggest new possible applications for these highly tuneable materials.}, note = {Online available at: \url{https://doi.org/10.1088/2516-1083/ac7499} (DOI). Dematteis, E.; Amdisen, M.; Autrey, T.; Barale, J.; Bowden, M.; Buckley, C.; Cho, Y.; Deledda, S.; Dornheim, M.; De Jongh, P.; Grinderslev, J.; Gizer, G.; Gulino, V.; Hauback, B.; Heere, M.; Heo, T.; Humphries, T.; Jensen, T.; Kang, S.; Lee, Y.; Li, H.; Li, S.; Møller, K.; Ngene, P.; Orimo, S.; Paskevicius, M.; Polanski, M.; Takagi, S.; Wan, L.; Wood, B.; Hirscher, M.; Baricco, M.: Hydrogen storage in complex hydrides: past activities and new trends. Progress in Energy. 2022. vol. 4, no. 3, 032009. DOI: 10.1088/2516-1083/ac7499}} @misc{pasquini_magnesium_and_2022, author={Pasquini, L., Sakaki, K., Akiba, E., Allendorf, M.D., Alvares, E., Ares, J.R., Babai, D., Baricco, M., Bellosta Von Colbe, J., Bereznitsky, M., Buckley, C.E., Cho, Y.W., Cuevas, F., De Rango, P., Dematteis, E.M., Denys, R.V., Dornheim, M., Fernández, J.F., Hariyadi, A., Hauback, B.C., Heo, T.W., Hirscher, M., Humphries, T.D., Huot, J., Jacob, I., Jensen, T.R., Jerabek, P., Kang, S.Y., Keilbart, N., Kim, H., Latroche, M., Leardini, F., Li, H., Ling, S., Lototskyy, M.V., Mullen, R., Orimo, S.-I., Paskevicius, M., Pistidda, C., Polanski, M., Puszkiel, J., Rabkin, E., Sahlberg, M., Sartori, S., Santhosh, A., Sato, T., Shneck, R.Z., Sørby, M.H., Shang, Y., Stavila, V., Suh, J.-Y., Suwarno, S., Thi Thu, L., Wan, L.F., Webb, C.J., Witman, M., Wan, C., Wood, B.C., Yartys, V.A.}, title={Magnesium- and intermetallic alloys-based hydrides for energy storage: modelling, synthesis and properties}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1088/2516-1083/ac7190}, abstract = {Hydrides based on magnesium and intermetallic compounds provide a viable solution to the challenge of energy storage from renewable sources, thanks to their ability to absorb and desorb hydrogen in a reversible way with a proper tuning of pressure and temperature conditions. Therefore, they are expected to play an important role in the clean energy transition and in the deployment of hydrogen as an efficient energy vector. This review, by experts of Task 40 'Energy Storage and Conversion based on Hydrogen' of the Hydrogen Technology Collaboration Programme of the International Energy Agency, reports on the latest activities of the working group 'Magnesium- and Intermetallic alloys-based Hydrides for Energy Storage'. The following topics are covered by the review: multiscale modelling of hydrides and hydrogen sorption mechanisms; synthesis and processing techniques; catalysts for hydrogen sorption in Mg; Mg-based nanostructures and new compounds; hydrides based on intermetallic TiFe alloys, high entropy alloys, Laves phases, and Pd-containing alloys. Finally, an outlook is presented on current worldwide investments and future research directions for hydrogen-based energy storage.}, note = {Online available at: \url{https://doi.org/10.1088/2516-1083/ac7190} (DOI). Pasquini, L.; Sakaki, K.; Akiba, E.; Allendorf, M.; Alvares, E.; Ares, J.; Babai, D.; Baricco, M.; Bellosta Von Colbe, J.; Bereznitsky, M.; Buckley, C.; Cho, Y.; Cuevas, F.; De Rango, P.; Dematteis, E.; Denys, R.; Dornheim, M.; Fernández, J.; Hariyadi, A.; Hauback, B.; Heo, T.; Hirscher, M.; Humphries, T.; Huot, J.; Jacob, I.; Jensen, T.; Jerabek, P.; Kang, S.; Keilbart, N.; Kim, H.; Latroche, M.; Leardini, F.; Li, H.; Ling, S.; Lototskyy, M.; Mullen, R.; Orimo, S.; Paskevicius, M.; Pistidda, C.; Polanski, M.; Puszkiel, J.; Rabkin, E.; Sahlberg, M.; Sartori, S.; Santhosh, A.; Sato, T.; Shneck, R.; Sørby, M.; Shang, Y.; Stavila, V.; Suh, J.; Suwarno, S.; Thi Thu, L.; Wan, L.; Webb, C.; Witman, M.; Wan, C.; Wood, B.; Yartys, V.: Magnesium- and intermetallic alloys-based hydrides for energy storage: modelling, synthesis and properties. Progress in Energy. 2022. vol. 4, no. 3, 032007. DOI: 10.1088/2516-1083/ac7190}} @misc{ghazanfari_largescale_synthesis_2022, author={Ghazanfari, M., Santhosh, A., Vrijmoed, J., Siemensmeyer, K., Peters, B., Dehnen, S., Jerabek, P., Thiele, G.}, title={Large-scale synthesis of mixed valence K3[Fe2S4] with high dielectric and ferrimagnetic characteristics}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1039/D2RA05200H}, abstract = {High yields of phase-pure K3[Fe2S4] are obtained using a fast, straight-forward, and efficient synthetic technique starting from the binary precursors K2S and FeS, and elemental sulphur. The compound indicates soft ferrimagnetic characteristics with magnetization of 15.23 A m2 kg−1 at 300 K due to the mixed valence of FeII/FeIII. Sintering at different temperatures allows the manipulation of the microstructure as well as the ratio of grains to grain boundaries. This results in a variation of dielectric and impedance properties. Samples sintered at 923 K demonstrate a dielectric constant (κ) of around 1750 at 1 kHz, which lies within the range of well-known high-κ dielectric materials, and an ionic conductivity of 4 × 10−2 mS cm−1 at room temperature. The compound has an optical band gap of around 2.0 eV, in agreement with tailored quantum chemical calculations. These results highlight its potential as a material comprising non-toxic and abundant elements for electronic and magnetic applications.}, note = {Online available at: \url{https://doi.org/10.1039/D2RA05200H} (DOI). Ghazanfari, M.; Santhosh, A.; Vrijmoed, J.; Siemensmeyer, K.; Peters, B.; Dehnen, S.; Jerabek, P.; Thiele, G.: Large-scale synthesis of mixed valence K3[Fe2S4] with high dielectric and ferrimagnetic characteristics. RSC Advances. 2022. vol. 12, no. 47, 30514-30521. DOI: 10.1039/D2RA05200H}} @misc{jin_transformation_kinetics_2022, author={Jin, O., Shang, Y., Huang, X., Szabó, D.V., Le, T.T., Wagner, S., Klassen, T., Kübel, C., Pistidda, C., Pundt, A.}, title={Transformation Kinetics of LiBH4–MgH2 for Hydrogen Storage}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.3390/molecules27207005}, abstract = {The reactive hydride composite (RHC) LiBH4–MgH2 is regarded as one of the most promising materials for hydrogen storage. Its extensive application is so far limited by its poor dehydrogenation kinetics, due to the hampered nucleation and growth process of MgB2. Nevertheless, the poor kinetics can be improved by additives. This work studied the growth process of MgB2 with varying contents of 3TiCl3·AlCl3 as an additive, and combined kinetic measurements, X-ray diffraction (XRD), and advanced transmission electron microscopy (TEM) to develop a structural understanding. It was found that the formation of MgB2 preferentially occurs on TiB2 nanoparticles. The major reason for this is that the elastic strain energy density can be reduced to ~4.7 × 107 J/m3 by creating an interface between MgB2 and TiB2, as opposed to ~2.9 × 108 J/m3 at the original interface between MgB2 and Mg. The kinetics of the MgB2 growth was modeled by the Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation, describing the kinetics better than other kinetic models. It is suggested that the MgB2 growth rate-controlling step is changed from interface- to diffusion-controlled when the nucleation center changes from Mg to TiB2. This transition is also reflected in the change of the MgB2 morphology from bar- to platelet-like. Based on our observations, we suggest that an additive content between 2.5 and 5 mol% 3TiCl3·AlCl3 results in the best enhancement of the dehydrogenation kinetics.}, note = {Online available at: \url{https://doi.org/10.3390/molecules27207005} (DOI). Jin, O.; Shang, Y.; Huang, X.; Szabó, D.; Le, T.; Wagner, S.; Klassen, T.; Kübel, C.; Pistidda, C.; Pundt, A.: Transformation Kinetics of LiBH4–MgH2 for Hydrogen Storage. Molecules. 2022. vol. 27, no. 20, 7005. DOI: 10.3390/molecules27207005}} @misc{shang_effects_of_2022, author={Shang, Y., Jin, O., Puszkiel, J., Karimi, F., Dansirima, P., Sittiwet, C., Utke, R., Soontaranon, S., Le, T., Gizer, G., Szabó, D., Wagner, S., Kübel, C., Klassen, T., Dornheim, M., Pundt, A., Pistidda, C.}, title={Effects of metal-based additives on dehydrogenation process of 2NaBH4 + MgH2 system}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2022.08.293}, abstract = {We report a systematic investigation of the effect that selected metal-based additives have on the dehydrogenation properties of the reactive hydride composite (RHC) model system 2NaBH4+MgH2. Compared to the pristine system, the material doped with 3TiCl3·AlCl3 exhibits superior dehydrogenation kinetics. The addition of 3TiCl3·AlCl3 alters the controlling mechanism of the second dehydrogenation step making it change from a two-dimensional interface controlled process to a two-dimensional nucleation and growth controlled process. The microstructural investigation of the dehydrogenated 2NaBH4+MgH2 via high-resolution transmission electron microscopy (HRTEM) shows significant differences in the MgB2 morphology formed in the doped and undoped systems. The MgB2 has a needle-like structure in the sample doped with 3TiCl3·AlCl3, which is different from the plate-like MgB2 structure in the undoped sample. Moreover, nanostructured metal-based phases, such as TiB2/AlB2 particles, acting as heterogeneous nucleation sites for MgB2 are also identified for the sample doped with 3TiCl3·AlCl3.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2022.08.293} (DOI). Shang, Y.; Jin, O.; Puszkiel, J.; Karimi, F.; Dansirima, P.; Sittiwet, C.; Utke, R.; Soontaranon, S.; Le, T.; Gizer, G.; Szabó, D.; Wagner, S.; Kübel, C.; Klassen, T.; Dornheim, M.; Pundt, A.; Pistidda, C.: Effects of metal-based additives on dehydrogenation process of 2NaBH4 + MgH2 system. International Journal of Hydrogen Energy. 2022. vol. 47, no. 89, 37882-37894. DOI: 10.1016/j.ijhydene.2022.08.293}} @misc{jerabek_relativistic_effects_2022, author={Jerabek, P., Santhosh, A., Schwerdtfeger, P.}, title={Relativistic Effects Stabilize Unusual Gold(II) Sulfate Structure via Aurophilic Interactions}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.inorgchem.2c01512}, abstract = {The crystal structure of gold(II) sulfate is strikingly different from other coinage metal(II) sulfates. Central to the unsual AuSO4 bulk structure is the Au24+ ion with a very close Au–Au contact, which is a structural feature that does not appear in CuSO4 and AgSO4. To shed some light on this unusual behavior, we decided to investigate the relative stabilities of the coinage metal(II) sulfates utilizing periodic Density Functional Theory. By computing relative energies of the hypothetical nonrelativistic gold(II) sulfate (AuNRSO4) in different structural arrangements and performing chemical bonding analyses employing the Electron Localization Function as well as the Quantum Theory of Atoms in Molecules method, we show that the stability of the unsual AuSO4 bulk structure can be related to aurophilic interactions enabled by relativistic effects. From the relative stabilities and UV–vis spectra computed via GW methodology, we predict that AuNRSO4 would assume the structure of either copper(II) sulfate or silver(II) sulfate with almost equal likelihood and appear as bright-violet or deep-blue substances, respectively.}, note = {Online available at: \url{https://doi.org/10.1021/acs.inorgchem.2c01512} (DOI). Jerabek, P.; Santhosh, A.; Schwerdtfeger, P.: Relativistic Effects Stabilize Unusual Gold(II) Sulfate Structure via Aurophilic Interactions. Inorganic Chemistry. 2022. vol. 61, no. 33, 13077-13084. DOI: 10.1021/acs.inorgchem.2c01512}} @misc{florez_from_the_2022, author={Florez, E., Smits, O., Mewes, J., Jerabek, P., Schwerdtfeger, P.}, title={From the gas phase to the solid state: The chemical bonding in the superheavy element flerovium}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1063/5.0097642}, abstract = {As early as 1975, Pitzer suggested that copernicium, flerovium, and oganesson are volatile substances behaving like noble gas because of their closed-shell configurations and accompanying relativistic effects. It is, however, precarious to predict the chemical bonding and physical behavior of a solid by knowledge of its atomic or molecular properties only. Copernicium and oganesson have been analyzed very recently by our group. Both are predicted to be semiconductors and volatile substances with rather low melting and boiling points, which may justify a comparison with the noble gas elements. Here, we study closed-shell flerovium in detail to predict its solid-state properties, including the melting point, by decomposing the total energy into many-body forces derived from relativistic coupled-cluster theory and from density functional theory. The convergence of such a decomposition for flerovium is critically analyzed, and the problem of using density functional theory is highlighted. We predict that flerovium in many ways does not behave like a typical noble gas element despite its closed-shell 7𝑝21/2 configuration and resulting weak interactions. Unlike the case of noble gases, the many-body expansion in terms of the interaction energy does not converge smoothly. This makes the accurate prediction of phase transitions very difficult. Nevertheless, a first prediction by Monte Carlo simulation estimates the melting point at 284 ± 50 K. Furthermore, calculations for the electronic bandgap suggests that flerovium is a semiconductor similar to copernicium}, note = {Online available at: \url{https://doi.org/10.1063/5.0097642} (DOI). Florez, E.; Smits, O.; Mewes, J.; Jerabek, P.; Schwerdtfeger, P.: From the gas phase to the solid state: The chemical bonding in the superheavy element flerovium. The Journal of Chemical Physics. 2022. vol. 157, no. 6, 064304. DOI: 10.1063/5.0097642}} @misc{ghazanfari_remarkable_infrared_2022, author={Ghazanfari, M.R., Vittadello, L., Al-Sabbagh, D., Santhosh, A., Frankcom, C., Fuß, F., von Randow, C.A., Siemensmeyer, K., Vrijmoed, J.C., Emmerling, F., Jerabek, P., Imlau, M., Thiele, G.}, title={Remarkable Infrared Nonlinear Optical, Dielectric, and Strong Diamagnetic Characteristics of Semiconducting K3[BiS3]}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.jpclett.2c01689}, abstract = {The ternary sulfido bismuthate K3[BiS3] is synthesized in quantitative yields. The material exhibits nonlinear optical properties with strong second harmonic generation properties at arbitrary wavelengths in the infrared spectral range and a notable laser-induced damage threshold of 5.22 GW cm–2 for pulsed laser radiation at a wavelength of 1040 nm, a pulse duration of 180 fs, and a repetition rate of 12.5 kHz. K3[BiS3] indicates semiconductivity with a direct optical band gap of 2.51 eV. Dielectric and impedance characterizations demonstrate κ values in the range of 6–13 at 1 kHz and a high electrical resistivity. A strong diamagnetic behavior with a susceptibility of −2.73 × 10–4 m3 kg–1 at room temperature is observed. These results suggest it is a promising nonlinear optical candidate for the infrared region. The synergic physical characteristics of K3[BiS3] provide insight into the correlation of optical, electrical, and magnetic properties.}, note = {Online available at: \url{https://doi.org/10.1021/acs.jpclett.2c01689} (DOI). Ghazanfari, M.; Vittadello, L.; Al-Sabbagh, D.; Santhosh, A.; Frankcom, C.; Fuß, F.; von Randow, C.; Siemensmeyer, K.; Vrijmoed, J.; Emmerling, F.; Jerabek, P.; Imlau, M.; Thiele, G.: Remarkable Infrared Nonlinear Optical, Dielectric, and Strong Diamagnetic Characteristics of Semiconducting K3[BiS3]. The Journal of Physical Chemistry Letters. 2022. vol. 13, no. 30, 6987-6993. DOI: 10.1021/acs.jpclett.2c01689}} @misc{dornheim_research_and_2022, author={Dornheim, M., Baetcke, L., Akiba, E., Ares, J., Autrey, T., Barale, J., Baricco, M., Brooks, K., Chalkiadakis, N., Charbonnier, V., Christensen, S., Bellosta von Colbe, J., Costamagna, M., Dematteis, E., Fernández, J., Gennett, T., Grant, D., Heo, T., Hirscher, M., Hurst, K., Lototskyy, M., Metz, O., Rizzi, P., Sakaki, K., Sartori, S., Stamatakis, E., Stuart, A., Stubos, A., Walker, G., Webb, C., Wood, B., Yartys, V., Zoulias, E.}, title={Research and development of hydrogen carrier based solutions for hydrogen compression and storage}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1088/2516-1083/ac7cb7}, abstract = {Recently, the industrial and public interest in hydrogen technologies has strongly risen, since hydrogen is the ideal means for medium to long term energy storage, transport and usage in combination with renewable and green energy supply. Therefore, in a future energy system the production, storage and usage of green hydrogen is a key technology. Hydrogen is and will in future be even more used for industrial production processes as reduction agent or for the production of synthetic hydrocarbons, especially in the chemical industry and refineries. Under certain conditions material based systems for hydrogen storage and compression offer advantages over the classical systems based on gaseous or liquid hydrogen. This includes in particular lower maintenance costs, higher reliability and safety. Hydrogen storage is possible at pressures and temperatures much closer to ambient conditions. Hydrogen compression is possible without any moving parts and only by using waste heat. In this paper, the newest developments of hydrogen carriers for storage and compression are summarized. In addition, an overview of the different research activities in this field are given.}, note = {Online available at: \url{https://doi.org/10.1088/2516-1083/ac7cb7} (DOI). Dornheim, M.; Baetcke, L.; Akiba, E.; Ares, J.; Autrey, T.; Barale, J.; Baricco, M.; Brooks, K.; Chalkiadakis, N.; Charbonnier, V.; Christensen, S.; Bellosta von Colbe, J.; Costamagna, M.; Dematteis, E.; Fernández, J.; Gennett, T.; Grant, D.; Heo, T.; Hirscher, M.; Hurst, K.; Lototskyy, M.; Metz, O.; Rizzi, P.; Sakaki, K.; Sartori, S.; Stamatakis, E.; Stuart, A.; Stubos, A.; Walker, G.; Webb, C.; Wood, B.; Yartys, V.; Zoulias, E.: Research and development of hydrogen carrier based solutions for hydrogen compression and storage. Progress in Energy. 2022. vol. 4, no. 4, 042005. DOI: 10.1088/2516-1083/ac7cb7}} @misc{ghazanfari_large_exchange_2022, author={Ghazanfari, M. R., Santhosh, A., Siemensmeyer, K., Fuß, F., Staab, L., Vrijmoed, J. C., Peters, B., Liesegang, M., Dehnen, S., Oeckler, O., Jerabek, P., Thiele, G.}, title={Large Exchange Bias, High Dielectric Constant, and Outstanding Ionic Conductivity in a Single-Phase Spin Glass}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1002/aelm.202200483}, abstract = {The multigram synthesis of K2[Fe3S4] starting from K2S and FeS is presented, and its electronic and magnetic properties are investigated. The title compound obtains a defect variant of the K[Fe2Se2] structure type. Dielectric and impedance measurements indicate a dielectric constant of 1120 at 1 kHz and an outstanding ionic conductivity of 24.37 mS cm–1 at 295 K, which is in the range of the highest reported value for potential solid-state electrolytes for potassium-ion batteries. The Seebeck coefficient of the n-type conductor amounts to −60 µV K−1 at 973 K. The mismatch of the measured electrical resistivity and the predicted metal-like band structure by periodic quantum chemical calculations indicates Mott insulating behavior. Magnetometry demonstrates temperature-dependent, large exchange bias fields of 35 mT, as a consequence of the coexistence of spin glass and antiferromagnetic orderings due to the iron vacancies in the lattice. In addition, the decreasing training effects of 34% in the exchange bias are identified at temperatures lower than 20 K. These results demonstrate the critical role of iron vacancies in tuning the electronic and magnetic properties and a multifunctional material from abundant and accessible elements.}, note = {Online available at: \url{https://doi.org/10.1002/aelm.202200483} (DOI). Ghazanfari, M.; Santhosh, A.; Siemensmeyer, K.; Fuß, F.; Staab, L.; Vrijmoed, J.; Peters, B.; Liesegang, M.; Dehnen, S.; Oeckler, O.; Jerabek, P.; Thiele, G.: Large Exchange Bias, High Dielectric Constant, and Outstanding Ionic Conductivity in a Single-Phase Spin Glass. Advanced Electronic Materials. 2022. vol. 8, no. 11, 2200483. DOI: 10.1002/aelm.202200483}} @misc{gleiner_operando_reaction_2022, author={Gleißner, R., Beck, E.E., Chung, S., Semione, G.D.L., Mukharamova, N., Gizer, G., Pistidda, C., Renner, D., Noei, H., Vonk, V., Stierle, A.}, title={Operando reaction cell for high energy surface sensitive x-ray diffraction and reflectometry}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1063/5.0098893}, abstract = {A proof of concept is shown for the design of a high pressure heterogeneous catalysis reaction cell suitable for surface sensitive x-ray diffraction and x-ray reflectometry over planar samples using high energy synchrotron radiation in combination with mass spectrometry. This design enables measurements in a pressure range from several tens to hundreds of bars for surface investigations under realistic industrial conditions in heterogeneous catalysis or gaseous corrosion studies.}, note = {Online available at: \url{https://doi.org/10.1063/5.0098893} (DOI). Gleißner, R.; Beck, E.; Chung, S.; Semione, G.; Mukharamova, N.; Gizer, G.; Pistidda, C.; Renner, D.; Noei, H.; Vonk, V.; Stierle, A.: Operando reaction cell for high energy surface sensitive x-ray diffraction and reflectometry. Review of Scientific Instruments. 2022. vol. 93, no. 7, 073902. DOI: 10.1063/5.0098893}} @misc{yartys_hydride4mobility_an_2021, author={Yartys, V.A., Lototskyy, M.V., Linkov, V., Pasupathi, S., Davids, M.W., Tolj, I., Radica, G., Denys, R.V., Eriksen, J., Taube, K., Bellosta von Colbe, J., Capurso, G., Dornheim, M., Smith, F., Mathebula, D., Swanepoel, D., Suwarno, S.}, title={HYDRIDE4MOBILITY: An EU HORIZON 2020 project on hydrogen powered fuel cell utility vehicles using metal hydrides in hydrogen storage and refuelling systems}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2021.01.190}, abstract = {This article gives an overview of HYDRIDE4MOBILITY project focused on the results generated during its first phase (2017–2019).}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2021.01.190} (DOI). Yartys, V.; Lototskyy, M.; Linkov, V.; Pasupathi, S.; Davids, M.; Tolj, I.; Radica, G.; Denys, R.; Eriksen, J.; Taube, K.; Bellosta von Colbe, J.; Capurso, G.; Dornheim, M.; Smith, F.; Mathebula, D.; Swanepoel, D.; Suwarno, S.: HYDRIDE4MOBILITY: An EU HORIZON 2020 project on hydrogen powered fuel cell utility vehicles using metal hydrides in hydrogen storage and refuelling systems. International Journal of Hydrogen Energy. 2021. vol. 46, no. 72, 35896-35909. DOI: 10.1016/j.ijhydene.2021.01.190}} @misc{nyamsi_200_nl_2021, author={Nyamsi, S., Lototsky, M., Yartys, V., Capurso, G., Davids, M., Pasupathi, S.}, title={200 NL H2 hydrogen storage tank using MgH2–TiH2–C nanocomposite as H storage material}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2021.03.055}, abstract = {MgH2-based hydrogen storage materials are promising candidates for solid-state hydrogen storage allowing efficient thermal management in energy systems integrating metal hydride hydrogen store with a solid oxide fuel cell (SOFC) providing dissipated heat at temperatures between 400 and 600 °C. Recently, we have shown that graphite-modified composite of TiH2 and MgH2 prepared by high-energy reactive ball milling in hydrogen (HRBM), demonstrates a high reversible gravimetric H storage capacity exceeding 5 wt % H, fast hydrogenation/dehydrogenation kinetics and excellent cycle stability. In present study, 0.9 MgH2 + 0.1 TiH2 +5 wt %C nanocomposite with a maximum hydrogen storage capacity of 6.3 wt% H was prepared by HRBM preceded by a short homogenizing pre-milling in inert gas. 300 g of the composite was loaded into a storage tank accommodating an air-heated stainless steel metal hydride (MH) container equipped with transversal internal (copper) and external (aluminium) fins. Tests of the tank were carried out in a temperature range from 150 °C (H2 absorption) to 370 °C (H2 desorption) and showed its ability to deliver up to 185 NL H2 corresponding to a reversible H storage capacity of the MH material of appr. 5 wt% H. No significant deterioration of the reversible H storage capacity was observed during 20 heating/cooling H2 discharge/charge cycles. It was found that H2 desorption performance can be tailored by selecting appropriate thermal management conditions and an optimal operational regime has been proposed.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2021.03.055} (DOI). Nyamsi, S.; Lototsky, M.; Yartys, V.; Capurso, G.; Davids, M.; Pasupathi, S.: 200 NL H2 hydrogen storage tank using MgH2–TiH2–C nanocomposite as H storage material. International Journal of Hydrogen Energy. 2021. vol. 46, no. 36, 19046-19059. DOI: 10.1016/j.ijhydene.2021.03.055}} @misc{daneshian_size_effects_2021, author={Daneshian, B., Gaertner, F., Assadi, H., Hoeche, D., Weber, W., Klassen, T.}, title={Size Effects of Brittle Particles in Aerosol Deposition—Molecular Dynamics Simulation}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s11666-020-01149-9}, abstract = {Up to now, the role of particle sizes on the impact behavior of ceramic particles in aerosol deposition not yet fully understood. Hence, with the aim to supply a more general understanding, modeling series of low strain rate compression and high-speed impact were performed by molecular dynamics on single-crystalline particles in sizes of 10-300 nm that are tuned to match mechanical properties of TiO2-anatase. The modeling results reveal that particles with original diameter of 25-75 nm exhibit three different impact behaviors that could be distinguished as (i) rebounding, (ii) bonding and (iii) fragmentation, depending on their initial impact velocity. In contrast, particles larger than 75 nm do not exhibit the bonding behavior. Detailed stress and strain field distributions reveal that combination of “localized inelastic deformation” along the slip systems and “shear localization” cause bonding of the small and large particles to the substrate. The analyses of associated temperature rise by the inelastic deformation revealed that heat diffusion at these small scales depend on size. Whereas small particles could reach a rather homogeneous temperature distribution, the evolved heat in the larger ones keeps rather localized to areas of highest deformation and may support deformation and the formation of dense layers in aerosol deposition.}, note = {Online available at: \url{https://doi.org/10.1007/s11666-020-01149-9} (DOI). Daneshian, B.; Gaertner, F.; Assadi, H.; Hoeche, D.; Weber, W.; Klassen, T.: Size Effects of Brittle Particles in Aerosol Deposition—Molecular Dynamics Simulation. Journal of Thermal Spray Technology. 2021. vol. 30, 503-522. DOI: 10.1007/s11666-020-01149-9}} @misc{wolpert_aerosoldeposited_bivo4_2021, author={Wolpert, C., Emmler, T., Vidaller, M., Elsenberg, A., Shinoda, K., Schieda, M., Gärtner, F., Akedo, J., Klassen, T.}, title={Aerosol-Deposited BiVO4 Photoelectrodes for Hydrogen Generation}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s11666-020-01104-8}, abstract = {Hydrogen generation from renewable energy sources will play a key role in the concerted endeavor to constrain climate change. One environmentally friendly route, powered by sunlight, is the photoelectrochemical water splitting cell (PEC). This technology employs electrodes coated with thin films of semiconductor materials to capture light and generate charge carriers that directly drive the water splitting reaction. Bismuth vanadate is a promising metal oxide semiconductor, as it absorbs visible light, and is abundant, non-toxic and cost-effective. The present study investigates the formation of bismuth vanadate thin films by the aerosol deposition (AD) method. Operating with layer formation at room temperature, AD offers advantages over other routes for the fabrication of photoactive thin film coatings, as no binders or sintering processes need to be applied. Furthermore, compared to traditional cold spraying, micrometer-sized particles can be used, resulting in coatings with thicknesses below 1 µm. Additionally, the lower kinetic energy of the feedstock powder particles enables the use of delicate substrates, such as FTO-coated glass, expanding the range of possible PEC device configurations. The process parameters explored in this study had considerable influence on the resulting coating microstructure, which in turn showed a significant impact on the photoelectrochemical performance.}, note = {Online available at: \url{https://doi.org/10.1007/s11666-020-01104-8} (DOI). Wolpert, C.; Emmler, T.; Vidaller, M.; Elsenberg, A.; Shinoda, K.; Schieda, M.; Gärtner, F.; Akedo, J.; Klassen, T.: Aerosol-Deposited BiVO4 Photoelectrodes for Hydrogen Generation. Journal of Thermal Spray Technology. 2021. vol. 30, 603-616. DOI: 10.1007/s11666-020-01104-8}} @misc{neves_modeling_the_2021, author={Neves, A.M., Puszkiel, J., Capurso, G., Bellosta von Colbe, J.M., Milanese, C., Dornheim, M., Klassen, T., Jepsen, J.}, title={Modeling the kinetic behavior of the Li-RHC system for energy-hydrogen storage: (I) absorption}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2021.06.227}, abstract = {The Lithium–Boron Reactive Hydride Composite System (Li-RHC) (2 LiH + MgB2/2 LiBH4 + MgH2) is a high-temperature hydrogen storage material suitable for energy storage applications. Herein, a comprehensive gas-solid kinetic model for hydrogenation is developed. Based on thermodynamic measurements under absorption conditions, the system's enthalpy ΔH and entropy ΔS are determined to amount to −34 ± 2 kJ∙mol H2−1 and −70 ± 3 J∙K−1∙mol H2−1, respectively. Based on the thermodynamic behavior assessment, the kinetic measurements' conditions are set in the range between 325 °C and 412 °C, as well as between 15 bar and 50 bar. The kinetic analysis shows that the hydrogenation rate-limiting-step is related to a one-dimensional interface-controlled reaction with a driving-force-corrected apparent activation energy of 146 ± 3 kJ∙mol H2−1. Applying the kinetic model, the dependence of the reaction rate constant as a function of pressure and temperature is calculated, allowing the design of optimized hydrogen/energy storage vessels via finite element method (FEM) simulations.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2021.06.227} (DOI). Neves, A.; Puszkiel, J.; Capurso, G.; Bellosta von Colbe, J.; Milanese, C.; Dornheim, M.; Klassen, T.; Jepsen, J.: Modeling the kinetic behavior of the Li-RHC system for energy-hydrogen storage: (I) absorption. International Journal of Hydrogen Energy. 2021. vol. 46, no. 63, 32110-32125. DOI: 10.1016/j.ijhydene.2021.06.227}} @misc{karimi_characterization_of_2021, author={Karimi, F., Börris, S., Pranzas, P., Metz, O., Hoell, A., Gizer, G., Puszkiel, J., Riglos, M., Pistidda, C., Dornheim, M., Klassen, T., Schreyer, A.}, title={Characterization of LiBH4–MgH2 Reactive Hydride Composite System with Scattering and Imaging Methods Using Neutron and Synchrotron Radiation}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1002/adem.202100294}, abstract = {Reversible solid-state hydrogen storage in metal hydrides is a key technology for pollution-free energy conversion systems. Herein, the LiBH2–MgH2 composite system with and without ScCl3 additive is investigated using synchrotron- and neutron-radiation-based probing methods that can be applied to characterize such lightweight metal–hydrogen systems from nanoscopic levels up to macroscopic scale. Combining the results of neutron- and photon-based methods allows a complementary insight into reaction paths and mechanisms, complex interactions between the hydride matrix and additive, hydrogen distribution, material transport, structural changes, and phase separation in the hydride matrix. The gained knowledge is of great importance for development and optimization of such novel metal-hydride-based hydrogen storage systems with respect to future applications.}, note = {Online available at: \url{https://doi.org/10.1002/adem.202100294} (DOI). Karimi, F.; Börris, S.; Pranzas, P.; Metz, O.; Hoell, A.; Gizer, G.; Puszkiel, J.; Riglos, M.; Pistidda, C.; Dornheim, M.; Klassen, T.; Schreyer, A.: Characterization of LiBH4–MgH2 Reactive Hydride Composite System with Scattering and Imaging Methods Using Neutron and Synchrotron Radiation. Advanced Engineering Materials. 2021. vol. 23, no. 11, 2100294. DOI: 10.1002/adem.202100294}} @misc{aslan_high_hydrogen_2021, author={Aslan, N., Gizer, G., Pistidda, C., Dornheim, M., Müller, M., Busch, S., Lohstroh, W.}, title={High Hydrogen Mobility in an Amide–Borohydride Compound Studied by Quasielastic Neutron Scattering}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1002/adem.202100620}, abstract = {The hydrogen storage performance of reactive hydride composite Mg(NH2)2+2LiH can be significantly improved by the addition of LiBH4 and the subsequent formation of an amide–borohydride compound Li4(BH4)(NH2)3 during hydrogen release. Herein, an investigation into the structure and anion motions of Li4(BH4)(NH2)3 using synchrotron radiation powder X-ray diffraction (SR-PXD; 295–573 K) and quasielastic neutron scattering (QENS; 297–514 K) is described. The highest temperature studied with QENS (514 K) is above the melting point of Li4(BH4)(NH2)3. The neutron measurements confirm a long-range diffusive motion of hydrogen-containing species with the diffusion coefficient 𝐷≈10−6 cm2 s−1. Interestingly, this value is comparable to that of Li+ diffusion inferred from conductivity measurements. SR-PXD confirms the recrystallization of Li4(BH4)(NH2)3 from the melt into the α-phase upon cooling. At temperatures below 514 K, localized rotational motions are observed that are attributed to (BH4)− tetrahedra units mainly undergoing rotations around the 𝐶3 axes. The activation energy for this thermally activated process is found to be 𝐸a=15.5±0.9 and 17.4±0.9 kJ mol−1 respectively for the two instrumental resolutions utilized in the QENS measurements, corresponding to observation times of 55 and 14 ps.}, note = {Online available at: \url{https://doi.org/10.1002/adem.202100620} (DOI). Aslan, N.; Gizer, G.; Pistidda, C.; Dornheim, M.; Müller, M.; Busch, S.; Lohstroh, W.: High Hydrogen Mobility in an Amide–Borohydride Compound Studied by Quasielastic Neutron Scattering. Advanced Engineering Materials. 2021. vol. 23, no. 11, 2100620. DOI: 10.1002/adem.202100620}} @misc{karimi_a_comprehensive_2021, author={Karimi, F., Pranzas, K., Puszkiel, J., Castro Riglos, V., Milanese, C., Vainio, U., Pistidda, C., Gizer, G., Klassen, T., Schreyer, A., Dornheim, M.}, title={A comprehensive study on lithium-based reactive hydride composite (Li-RHC) as a reversible solid-state hydrogen storage system toward potential mobile applications}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1039/D1RA03246A}, abstract = {Reversible solid-state hydrogen storage is one of the key technologies toward pollutant-free and sustainable energy conversion. The composite system LiBH4–MgH2 can reversibly store hydrogen with a gravimetric capacity of 13 wt%. However, its dehydrogenation/hydrogenation kinetics is extremely sluggish (∼40 h) which hinders its usage for commercial applications. In this work, the kinetics of this composite system is significantly enhanced (∼96%) by adding a small amount of NbF5. The catalytic effect of NbF5 on the dehydrogenation/hydrogenation process of LiBH4–MgH2 is systematically investigated using a broad range of experimental techniques such as in situ synchrotron radiation X-ray powder diffraction (in situ SR-XPD), X-ray absorption spectroscopy (XAS), anomalous small angle X-ray scattering (ASAXS), and ultra/small-angle neutron scattering (USANS/SANS). The obtained results are utilized to develop a model that explains the catalytic function of NbF5 in hydrogen release and uptake in the LiBH4–MgH2 composite system.}, note = {Online available at: \url{https://doi.org/10.1039/D1RA03246A} (DOI). Karimi, F.; Pranzas, K.; Puszkiel, J.; Castro Riglos, V.; Milanese, C.; Vainio, U.; Pistidda, C.; Gizer, G.; Klassen, T.; Schreyer, A.; Dornheim, M.: A comprehensive study on lithium-based reactive hydride composite (Li-RHC) as a reversible solid-state hydrogen storage system toward potential mobile applications. RSC Advances. 2021. vol. 11, no. 37, 23122-23135. DOI: 10.1039/D1RA03246A}} @misc{dematteis_fundamental_hydrogen_2021, author={Dematteis, E., Dreistadt, D., Capurso, G., Jepsen, J., Cuevas, F., Latroche, M.}, title={Fundamental hydrogen storage properties of TiFe-alloy with partial substitution of Fe by Ti and Mn}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2021.159925}, abstract = {TiFe intermetallic compound has been extensively studied, owing to its low cost, good volumetric hydrogen density, and easy tailoring of hydrogenation thermodynamics by elemental substitution. All these positive aspects make this material promising for large-scale applications of solid-state hydrogen storage. On the other hand, activation and kinetic issues should be amended and the role of elemental substitution should be further understood. This work investigates the thermodynamic changes induced by the variation of Ti content along the homogeneity range of the TiFe phase (Ti:Fe ratio from 1:1–1:0.9) and of the substitution of Mn for Fe between 0 and 5 at%. In all considered alloys, the major phase is TiFe-type together with minor amounts of TiFe2 or β-Ti-type and Ti4Fe2O-type at the Ti-poor and rich side of the TiFe phase domain, respectively. Thermodynamic data agree with the available literature but offer here a comprehensive picture of hydrogenation properties over an extended Ti and Mn compositional range. Moreover, it is demonstrated that Ti-rich alloys display enhanced storage capacities, as long as a limited amount of β-Ti is formed. Both Mn and Ti substitutions increase the cell parameter by possibly substituting Fe, lowering the plateau pressures and decreasing the hysteresis of the isotherms. A full picture of the dependence of hydrogen storage properties as a function of the composition will be discussed, together with some observed correlations.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2021.159925} (DOI). Dematteis, E.; Dreistadt, D.; Capurso, G.; Jepsen, J.; Cuevas, F.; Latroche, M.: Fundamental hydrogen storage properties of TiFe-alloy with partial substitution of Fe by Ti and Mn. Journal of Alloys and Compounds. 2021. vol. 874, 159925. DOI: 10.1016/j.jallcom.2021.159925}} @misc{thiangviriya_effects_of_2021, author={Thiangviriya, S., Plerdsranoy, P., Hagenah, A., Le, T.T., Kidkhunthod, P., Utke, O., Dornheim, M., Klassen, T., Pistidda, C., Utke, R.}, title={Effects of Ni-loading contents on dehydrogenation kinetics and reversibility of Mg2FeH6}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2021.06.206}, abstract = {Although Mg2FeH6 has drawn significant attention for storing hydrogen, its sluggish kinetics during hydrogenation and poor reversibility hinder practical uses. In this work, the replacement of Fe atoms in Mg2FeH6 with Ni atoms is attempted and the material properties are investigated. A detailed study of the de/rehydrogenation kinetics and reaction mechanisms of the Ni-doped Mg2FeH6 is carried out. The effects of Ni-loading contents on kinetic properties and behaviors as well as reversibility and reaction pathways are characterized. In addition, the crystal structure of a new Ni-substituted Mg2FeH6 phase is confirmed.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2021.06.206} (DOI). Thiangviriya, S.; Plerdsranoy, P.; Hagenah, A.; Le, T.; Kidkhunthod, P.; Utke, O.; Dornheim, M.; Klassen, T.; Pistidda, C.; Utke, R.: Effects of Ni-loading contents on dehydrogenation kinetics and reversibility of Mg2FeH6. International Journal of Hydrogen Energy. 2021. vol. 46, no. 63, 32099-32109. DOI: 10.1016/j.ijhydene.2021.06.206}} @misc{le_enhanced_hydrogen_2021, author={Le, T.-T., Pistidda, C., Puszkiel, J., Riglos, M.V.C., Dreistadt, D.M., Klassen, T., Dornheim, M.}, title={Enhanced Hydrogen Storage Properties of Li-RHC System with In-House Synthesized AlTi3 Nanoparticles}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.3390/en14237853}, abstract = {In recent years, the use of selected additives for improving the kinetic behavior of the system 2LiH + MgB2 (Li-RHC) has been investigated. As a result, it has been reported that some additives (e.g., 3TiCl3·AlCl3), by reacting with the Li-RHC components, form nanostructured phases (e.g., AlTi3) possessing peculiar microstructural properties capable of enhancing the system’s kinetic behavior. The effect of in-house-produced AlTi3 nanoparticles on the hydrogenation/dehydrogenation kinetics of the 2LiH + MgB2 (Li-RHC) system is explored in this work, with the aim of reaching high hydrogen storage performance. Experimental results show that the AlTi3 nanoparticles significantly improve the reaction rate of the Li-RHC system, mainly for the dehydrogenation process. The observed improvement is most likely due to the similar structural properties between AlTi3 and MgB2 phases which provide an energetically favored path for the nucleation of MgB2. In comparison with the pristine material, the Li-RHC doped with AlTi3 nanoparticles has about a nine times faster dehydrogenation rate. The results obtained from the kinetic modeling indicate a change in the Li-RHC hydrogenation reaction mechanism in the presence of AlTi3 nanoparticles.}, note = {Online available at: \url{https://doi.org/10.3390/en14237853} (DOI). Le, T.; Pistidda, C.; Puszkiel, J.; Riglos, M.; Dreistadt, D.; Klassen, T.; Dornheim, M.: Enhanced Hydrogen Storage Properties of Li-RHC System with In-House Synthesized AlTi3 Nanoparticles. Energies. 2021. vol. 14, no. 23, 7853. DOI: 10.3390/en14237853}} @misc{le_nanoconfinement_effects_2021, author={Le, T., Pistidda, C., Nguyen, V., Singh, P., Raizada, P., Klassen, T., Dornheim, M.}, title={Nanoconfinement effects on hydrogen storage properties of MgH2 and LiBH4}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2021.04.150}, abstract = {To find a solution to efficiently exploit renewable energy sources is a key step to achieve complete independence from fossil fuel energy sources. Hydrogen is considered by many as a suitable energy vector for efficiently exploiting intermittent and unevenly distributed renewable energy sources. However, although the production of hydrogen from renewable energy sources is technically feasible, the storage of large quantities of hydrogen is challenging. Comparing to conventional compressed and cryogenic hydrogen storage, the solid-state storage of hydrogen shows many advantages in terms of safety and volumetric energy density. Among the materials available to store hydrogen, metal hydrides and complex metal hydrides have been extensively investigated due to their appealing hydrogen storage properties. Among several potentials candidates, magnesium hydride (MgH2) and lithium borohydride (LiBH4) have been widely recognized as promising solid-state hydrogen storage materials. However, before considering these hydrides ready for real-scale applications, the issue of their high thermodynamic stability and of their poor hydrogenation/dehydrogenation kinetics must be solved. An approach to modify the hydrogen storage properties of these hydrides is nanoconfinement. This review summarizes and discusses recent findings on the use of porous scaffolds as nanostructured tools for improving the thermodynamics and kinetics of MgH2 and LiBH4.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2021.04.150} (DOI). Le, T.; Pistidda, C.; Nguyen, V.; Singh, P.; Raizada, P.; Klassen, T.; Dornheim, M.: Nanoconfinement effects on hydrogen storage properties of MgH2 and LiBH4. International Journal of Hydrogen Energy. 2021. vol. 46, no. 46, 23723-23736. DOI: 10.1016/j.ijhydene.2021.04.150}} @misc{pistidda_hydrogenation_via_2021, author={Pistidda, C., Santhosh, A., Jerabek, P., Shang, Y., Girella, A., Milanese, C., Dore, M., Garroni, S., Bordignon, S., Chierotti, M.R., Klassen, T., Dornheim, M.}, title={Hydrogenation via a low energy mechanochemical approach: the MgB2 case}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1088/2515-7655/abf81b}, abstract = {This work aims at investigating the effect that the energy transferred during particle collisions in a milling process entails on solid-gas reactions. For this purpose, the synthesis of Mg(BH4)2 from MgB2 in a pressurized hydrogen atmosphere was chosen as a model reaction. MgB2 was milled under a broad set of milling parameters (i.e. milling times and rotation regimes) and the obtained product thoroughly characterized. By proving the partial formation of Mg(BH4)2, the results of this investigation indicate that the energy transferred to the powder bed by the powder particles during milling is not negligible, in particular when the milling process is protracted for a long period.}, note = {Online available at: \url{https://doi.org/10.1088/2515-7655/abf81b} (DOI). Pistidda, C.; Santhosh, A.; Jerabek, P.; Shang, Y.; Girella, A.; Milanese, C.; Dore, M.; Garroni, S.; Bordignon, S.; Chierotti, M.; Klassen, T.; Dornheim, M.: Hydrogenation via a low energy mechanochemical approach: the MgB2 case. JPhys Energy. 2021. vol. 3, no. 4, 044001. DOI: 10.1088/2515-7655/abf81b}} @misc{bondue_suppression_of_2021, author={Bondue, C., Graf, M., Goyal, A., Koper, M.}, title={Suppression of Hydrogen Evolution in Acidic Electrolytes by Electrochemical CO2 Reduction}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jacs.0c10397}, abstract = {In this article we investigate the electrochemical reduction of CO2 at gold electrodes under mildly acidic conditions. Differential electrochemical mass spectroscopy (DEMS) is used to quantify the amounts of formed hydrogen and carbon monoxide as well as the consumed amount of CO2. We investigate how the Faradaic efficiency of CO formation is affected by the CO2 partial pressure (0.1–0.5 bar) and the proton concentration (1–0.25 mM). Increasing the former enhances the rate of CO2 reduction and suppresses hydrogen evolution from proton reduction, leading to Faradaic efficiencies close to 100%. Hydrogen evolution is suppressed by CO2 reduction as all protons at the electrode surfaces are used to support the formation of water (CO2 + 2H+ + 2e– → CO + H2O). Under conditions of slow mass transport, this leaves no protons to support hydrogen evolution. On the basis of our results, we derive a general design principle for acid CO2 electrolyzers to suppress hydrogen evolution from proton reduction: the rate of CO/OH– formation must be high enough to match/compensate the mass transfer of protons to the electrode surface.}, note = {Online available at: \url{https://doi.org/10.1021/jacs.0c10397} (DOI). Bondue, C.; Graf, M.; Goyal, A.; Koper, M.: Suppression of Hydrogen Evolution in Acidic Electrolytes by Electrochemical CO2 Reduction. Journal of the American Chemical Society. 2021. vol. 143, no. 1, 279-285. DOI: 10.1021/jacs.0c10397}} @misc{wang_hydrogen_storage_2021, author={Wang, J., Lei, G., Pistidda, C., He, T., Cao, H., Dornheim, M., Chen, P.}, title={Hydrogen storage properties and reaction mechanisms of K2Mn(NH2)4–8LiH system}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2021.09.216}, abstract = {Hydrogen storage properties of K2Mn(NH2)4–8LiH were investigated by considering its de/re-hydrogenation properties and reaction mechanisms. Experimental results show that the dehydrogenated K2Mn(NH2)4–8LiH can be almost re-hydrogenated completely at 230 °C and 50 bar of H2 with a hydrogenation rate more than 1.0 wt%/min. In-situ synchrotron radiation powder X-ray diffraction (SR-PXD) and FTIR investigations reveal that during ball milling K2Mn(NH2)4 reacts with LiH to form LiNH2 and K–Mn-species1 which is probably a K–Mn-containing hydride. The ball milled sample releases hydrogen in a multi-step reaction with the formation of K3MnH5 and K–Mn-species2 as intermediates and Li2NH, Mn3N2 and MnN as final products. The full hydrogenated products are LiH, LiNH2, and K–Mn-species2. The K–Mn-species2 may play a critical role for the fast hydrogeneration. This work indicates that transition metal contained amide-hydride composite holds potentials for hydrogen storage.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2021.09.216} (DOI). Wang, J.; Lei, G.; Pistidda, C.; He, T.; Cao, H.; Dornheim, M.; Chen, P.: Hydrogen storage properties and reaction mechanisms of K2Mn(NH2)4–8LiH system. International Journal of Hydrogen Energy. 2021. vol. 46, no. 80, 40196-40202. DOI: 10.1016/j.ijhydene.2021.09.216}} @misc{gleiner_copper_nanoparticles_2021, author={Gleißner, R., Noei, H., Chung, S., Semione, G.D.L., Beck, E.E., Dippel, A.-C., Gutowski, O., Gizer, G., Vonk, V., Stierle, A.}, title={Copper Nanoparticles with High Index Facets on Basal and Vicinal ZnO Surfaces}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.jpcc.1c08008}, abstract = {We investigated the orientation and morphology of Cu nanoparticles grown under ultrahigh-vacuum conditions on ZnO(0001), ZnO(0001̅), and ZnO(101̅4) single crystal surfaces by scanning tunneling microscopy, high-energy grazing incidence X-ray diffraction, low-energy electron diffraction, and scanning electron microscopy. The (111) oriented Cu NPs on basal ZnO showed only small area fractions of high indexed Cu(225) and Cu(331) facets. Cu NPs grown on ZnO(101̅4) show alignment of Cu [111] with the ZnO [0001] direction, which is at an angle of 24.8° to the ZnO(101̅4) surface normal. Because of this tilt, the NPs exhibit a shape with a larger fraction of high indexed facets such as (335), (221), (113), and (551̅). In addition, the direct interaction of subsequent Cu(111) planes to the underlying substrate results in unequal amounts of ABCA and ACBA stacked NPs. Small NPs are found to interact strongly with the vicinal surface, giving rise to a surface corrugation with a multiple of the surface step distance. The high density of low-coordinated Cu surface atoms potentially increases the overall catalytic activity for methanol synthesis and CO2 hydrogenation reactions.}, note = {Online available at: \url{https://doi.org/10.1021/acs.jpcc.1c08008} (DOI). Gleißner, R.; Noei, H.; Chung, S.; Semione, G.; Beck, E.; Dippel, A.; Gutowski, O.; Gizer, G.; Vonk, V.; Stierle, A.: Copper Nanoparticles with High Index Facets on Basal and Vicinal ZnO Surfaces. The Journal of Physical Chemistry C. 2021. vol. 125, no. 42, 23561-23569. DOI: 10.1021/acs.jpcc.1c08008}} @misc{hasija_stepscheme_heterojunction_2021, author={Hasija, V., Kumar, A., Sudhaik, A., Raizada, P., Singh, P., Van Le, Q., Le, T.T., Nguyen, V.-H.}, title={Step-scheme heterojunction photocatalysts for solar energy, water splitting, CO2 conversion, and bacterial inactivation: a review}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s10311-021-01231-w}, abstract = {Solar radiation is a sustainable, unlimited source of energy for electricity and chemical reactions, yet the conversion efficiency of actual processes is limited and controlled by photocarriers migration and separation. Enhancing the conversion efficiency would require to suppress the recombination of photogenerated electron–hole pairs and improve the low redox potentials. This can be done during the growth of step-scheme (S-scheme) heterojunctions. Here we review the charge transfer of S-scheme heterojunctions involving a reduction and oxidation photocatalyst in staggered band arrangement with Fermi level differences. We present factors determining the validation of the S-scheme mechanism with respective characterization techniques, including in situ and ex situ experiments, and theoretical studies. We show mechanistic drawbacks of traditional photocatalytic systems to highlight the advantages of S-scheme photocatalysts. We describe co-catalyst loading, bandgap tuning, and interfacial optimization that ultimately achieve highly efficient photocatalysis. Last, application for water splitting, CO2 conversion, pollutant degradation, bacterial inactivation and others is discussed.}, note = {Online available at: \url{https://doi.org/10.1007/s10311-021-01231-w} (DOI). Hasija, V.; Kumar, A.; Sudhaik, A.; Raizada, P.; Singh, P.; Van Le, Q.; Le, T.; Nguyen, V.: Step-scheme heterojunction photocatalysts for solar energy, water splitting, CO2 conversion, and bacterial inactivation: a review. Environmental Chemistry Letters. 2021. vol. 19, no. 4, 2941-2966. DOI: 10.1007/s10311-021-01231-w}} @misc{shang_mgbased_materials_2021, author={Shang, Y., Pistidda, C., Gizer, G., Klassen, T., Dornheim, M.}, title={Mg-based materials for hydrogen storage}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jma.2021.06.007}, abstract = {Over the last decade's magnesium and magnesium based compounds have been intensively investigated as potential hydrogen storage as well as thermal energy storage materials due to their abundance and availability as well as their extraordinary high gravimetric and volumetric storage densities. This review work provides a broad overview of the most appealing systems and of their hydrogenation/dehydrogenation properties. Special emphasis is placed on reviewing the efforts made by the scientific community in improving the material's thermodynamic and kinetic properties while maintaining a high hydrogen storage capacity.}, note = {Online available at: \url{https://doi.org/10.1016/j.jma.2021.06.007} (DOI). Shang, Y.; Pistidda, C.; Gizer, G.; Klassen, T.; Dornheim, M.: Mg-based materials for hydrogen storage. Journal of Magnesium and Alloys. 2021. vol. 9, no. 6, 1837-1860. DOI: 10.1016/j.jma.2021.06.007}} @misc{soni_sustainable_and_2021, author={Soni, V., Raizada, P., Singh, P., Cuong, H.N.S.R., Saini, A., Saini, R.V., Le, Q.V., Nadda, A.K., Le, T.-T., Nguyen, V.-H.}, title={Sustainable and green trends in using plant extracts for the synthesis of biogenic metal nanoparticles toward environmental and pharmaceutical advances: A review}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.envres.2021.111622}, abstract = {Conventionally utilized physical and chemical routes for constructing nanoparticles are not eco-friendly. They are associated with many shortcomings like the requirement of specially designed equipment, templates, extremely high temperature, and pressure. Biosynthesis seems to be drawn unequivocal attention owing to its upsurge of applications in different fields like; energy, nutrition, pharmaceutical, and medicinal sciences. To harness the biological sources, the present review describes an environment-friendly route to generate biogenic nanoparticles from the natural plant extracts and the followed mechanisms for their synthesis, growth, and stabilization. The present review summarizes the recent trends involved in the photosynthesis of metallic nanoparticles and their effective use in controlling malaria, hepatitis, cancer, like various endemic diseases. Also, various characterization approaches, such as UV–visible spectrophotometry, Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy, are discussed here examine the properties of as-fabricated nanoparticles. Various plant parts like leaves, stems, barks, fruit, and flowers are rich in flavonoids, phenols, steroids, terpenoids, enzymes, and alkaloids, thereby playing an essential role in reducing metal ions that generate metallic nanoparticles. Herein, the uniqueness of phytofabricated nanoparticles along with their distinctive antibacterial, antioxidant, cytotoxic, and drug delivery properties are featured. Lastly, this work highlights the various challenges and future perspectives to further synthesize biogenic metal nanoparticles toward environmental and pharmaceutical advances in the coming years.}, note = {Online available at: \url{https://doi.org/10.1016/j.envres.2021.111622} (DOI). Soni, V.; Raizada, P.; Singh, P.; Cuong, H.; Saini, A.; Saini, R.; Le, Q.; Nadda, A.; Le, T.; Nguyen, V.: Sustainable and green trends in using plant extracts for the synthesis of biogenic metal nanoparticles toward environmental and pharmaceutical advances: A review. Environmental Research. 2021. vol. 202, 111622. DOI: 10.1016/j.envres.2021.111622}} @misc{pistidda_solidstate_hydrogen_2021, author={Pistidda, C.}, title={Solid-State Hydrogen Storage for a Decarbonized Society}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.3390/hydrogen2040024}, abstract = {Humanity is confronted with one of the most significant challenges in its history. The excessive use of fossil fuel energy sources is causing extreme climate change, which threatens our way of life and poses huge social and technological problems. It is imperative to look for alternate energy sources that can replace environmentally destructive fossil fuels. In this scenario, hydrogen is seen as a potential energy vector capable of enabling the better and synergic exploitation of renewable energy sources. A brief review of the use of hydrogen as a tool for decarbonizing our society is given in this work. Special emphasis is placed on the possibility of storing hydrogen in solid-state form (in hydride species), on the potential fields of application of solid-state hydrogen storage, and on the technological challenges solid-state hydrogen storage faces. A potential approach to reduce the carbon footprint of hydrogen storage materials is presented in the concluding section of this paper.}, note = {Online available at: \url{https://doi.org/10.3390/hydrogen2040024} (DOI). Pistidda, C.: Solid-State Hydrogen Storage for a Decarbonized Society. Hydrogen. 2021. vol. 2, no. 4, 428-443. DOI: 10.3390/hydrogen2040024}} @misc{caggiu_in_situ_2020, author={Caggiu, L., Iacomini, A., Pistidda, C., Farina, V., Senes, N., Cao, H., Gavini, E., Mulas, G., Garroni, S., Enzo, S.}, title={In situ synchrotron radiation investigation of V2O5–Nb2O5 metastable compounds: transformational kinetics at high temperatures with a new structural solution for the orthorhombic V4Nb20O60 phase}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1039/d0dt03426f}, abstract = {Due to the considerable interest in vanadium niobium oxides as a lithium storage material, the kinetics and transformation processes of the V2O5–5Nb2O5 system have been investigated by in situ synchrotron powder X-ray diffraction. The diffraction data after the thermal treatments selected with a view on the most significant features were supplemented with specific ex situ experiments conducted using a laboratory rotating anode X-ray diffractometer. The morphological changes of the mixed powders assuming an amorphous and nanocrystalline solid solution structure as a function of the temperature were inspected by scanning electron microscopy observations. The structural solution of the powder diffraction pattern of the phase recorded in situ at a temperature of about 700 °C was compatible with an orthorhombic crystal structure with the space group Amm2. The obtained lattice parameters for this structure were a = 3.965 Å; b = 17.395 Å, c = 17.742 Å, and the cell composition was V4Nb20O60, Pearson symbol oA84, and density = 4.10 g cm−3. In this structure, while the niobium atoms may be four-, five-, and six-fold coordinated by oxygen atoms, the vanadium atoms were six-fold or seven-fold coordinated. At the temperature of 800 °C and just above, the selected 1 : 2 and 1 : 3 V2O5–Nb2O5 compositions, respectively, returned mostly a tetragonal VNb9O25 phase, in line with earlier observations conducted for determination of the stability phase diagram of such quasi-binary systems.}, note = {Online available at: \url{https://doi.org/10.1039/d0dt03426f} (DOI). Caggiu, L.; Iacomini, A.; Pistidda, C.; Farina, V.; Senes, N.; Cao, H.; Gavini, E.; Mulas, G.; Garroni, S.; Enzo, S.: In situ synchrotron radiation investigation of V2O5–Nb2O5 metastable compounds: transformational kinetics at high temperatures with a new structural solution for the orthorhombic V4Nb20O60 phase. Dalton Transactions. 2020. vol. 49, no. 48, 17584-17593. DOI: 10.1039/d0dt03426f}} @misc{chirumamilla_thermal_stability_2020, author={Chirumamilla, M., Krishnamurthy, G., Rout, S., Ritter, M., Störmer, M., Petrov, A., Eich, M.}, title={Thermal stability of tungsten based metamaterial emitter under medium vacuum and inert gas conditions}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1038/s41598-020-60419-2}, abstract = {Commercial deployment of thermophotovoltaics (TPV) is lacking behind the implementation of solar PV technology due to limited thermal stability of the selective emitter structures. Most of the TPV emitters demonstrated so far are designed to operate under high vacuum conditions (~10−6 mbar vacuum pressure), whereas under medium vacuum conditions (~10−2 mbar vacuum pressure), which are feasible in technical implementations of TPV, these emitters suffer from oxidation due to significant O2 partial pressure. In this work, the thermal stability of 1D refractory W-HfO2 based multilayered metamaterial emitter structure is investigated under different vacuum conditions. The impact of the O2 partial pressure on thermal stability of the emitters is experimentally quantified. We show that, under medium vacuum conditions, i.e. ~10−2 mbar vacuum pressure, the emitter shows unprecedented thermal stability up to 1300 °C when the residual O2 in the annealing chamber is minimized by encapsulating the annealing chamber with Ar atmosphere. This study presents a significant step in the experimental implementation of high temperature stable emitters under medium vacuum conditions, and their potential in construction of economically viable TPV systems. The high TPV efficiency, ~50% spectral efficiency for GaSb PV cell at 1300 °C, and high temperature stability make this platform well suited for technical application in next-generation TPV systems.}, note = {Online available at: \url{https://doi.org/10.1038/s41598-020-60419-2} (DOI). Chirumamilla, M.; Krishnamurthy, G.; Rout, S.; Ritter, M.; Störmer, M.; Petrov, A.; Eich, M.: Thermal stability of tungsten based metamaterial emitter under medium vacuum and inert gas conditions. Scientific Reports. 2020. vol. 10, 3605. DOI: 10.1038/s41598-020-60419-2}} @misc{aslan_highpressure_cell_2020, author={Aslan, N., Horstmann, C., Metz, O., Kotlyar, O., Dornheim, M., Pistidda, C., Busch, S., Lohstroh, W., Müller, M., Pranzas, K.}, title={High-pressure cell for in situ neutron studies of hydrogen storage materials}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.3233/JNR-190116}, abstract = {A high- pressure cell for neutron experiments was developed at Helmholtz-Zentrum Geesthacht (HZG). This cell is designed for the investigation of hydrogen storage materials at pressures up to 700 bar and temperatures up to 500°C. The idea is to have a prototype cell for different neutron scattering methods (diffraction, time- of-flight spectroscopy and small-angle neutron scattering). In this work, we discuss the development and the current state of the high- pressure cell. Furthermore, the deployment of the cell for in situ small-angle neutron scattering measurements on 6Mg(NH2 )2 + 9LiH + LiBH4 (6:9:1) at the instrument SANS-1 at Heinz Maier-Leibnitz Zentrum (MLZ) is demonstrated.}, note = {Online available at: \url{https://doi.org/10.3233/JNR-190116} (DOI). Aslan, N.; Horstmann, C.; Metz, O.; Kotlyar, O.; Dornheim, M.; Pistidda, C.; Busch, S.; Lohstroh, W.; Müller, M.; Pranzas, K.: High-pressure cell for in situ neutron studies of hydrogen storage materials. Journal of Neutron Research. 2020. vol. 21, no. 3 - 4, 125-135. DOI: 10.3233/JNR-190116}} @misc{buchsteiner_catalytic_asymmetric_2020, author={Buchsteiner, M., Martinez-Rodriguez, L., Jerabek, P., Pozo, I., Patzer, M., Nöthling, N., Lehmann, C., Fürstner, A.}, title={Catalytic Asymmetric Fluorination of Copper Carbene Complexes: Preparative Advances and a Mechanistic Rationale}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1002/chem.202000081}, abstract = {The Cu‐catalyzed reaction of substituted α‐diazoesters with fluoride gives α‐fluoroesters with ee values of up to 95 %, provided that chiral indane‐derived bis(oxazoline) ligands are used that carry bulky benzyl substituents at the bridge and moderately bulky isopropyl groups on their core. The apparently homogeneous solution of CsF in C6F6/hexafluoroisopropanol (HFIP) is the best reaction medium, but CsF in the biphasic mixture CH2Cl2/HFIP also provides good results. DFT studies suggest that fluoride initially attacks the Cu‐ rather than the C‐atom of the transient donor/acceptor carbene intermediate. This unusual step is followed by 1,2‐fluoride shift; for this migratory insertion to occur, the carbene must rotate about the Cu−C bond to ensure orbital overlap. The directionality of this rotatory movement within the C2‐symmetric binding site determines the sense of induction. This model is in excellent accord with the absolute configuration of the resulting product as determined by X‐ray diffraction using single crystals of this a priori wax‐like material grown by capillary crystallization.}, note = {Online available at: \url{https://doi.org/10.1002/chem.202000081} (DOI). Buchsteiner, M.; Martinez-Rodriguez, L.; Jerabek, P.; Pozo, I.; Patzer, M.; Nöthling, N.; Lehmann, C.; Fürstner, A.: Catalytic Asymmetric Fluorination of Copper Carbene Complexes: Preparative Advances and a Mechanistic Rationale. Chemistry - A European Journal. 2020. vol. 26, no. 11, 2509-2515. DOI: 10.1002/chem.202000081}} @misc{hadjixenophontos_erratum_hadjixenophontos_2020, author={Hadjixenophontos, E., Dematteis, E., Berti, N., Wolczyk, A., Huen, P., Brighi, M., Le, T., Santoru, A., Payandeh, S., Peru, F., Dao, A., Liu, Y., Heere, M.}, title={Erratum: Hadjixenophontos, E.; et al. A Review of the MSCA ITN ECOSTORE—Novel Complex Metal Hydrides for Efficient and Compact Storage of Renewable Energy as Hydrogen and Electricity. Inorganics 2020, 8, 17}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.3390/inorganics8110063}, note = {Online available at: \url{https://doi.org/10.3390/inorganics8110063} (DOI). Hadjixenophontos, E.; Dematteis, E.; Berti, N.; Wolczyk, A.; Huen, P.; Brighi, M.; Le, T.; Santoru, A.; Payandeh, S.; Peru, F.; Dao, A.; Liu, Y.; Heere, M.: Erratum: Hadjixenophontos, E.; et al. A Review of the MSCA ITN ECOSTORE—Novel Complex Metal Hydrides for Efficient and Compact Storage of Renewable Energy as Hydrogen and Electricity. Inorganics 2020, 8, 17. Inorganics. 2020. vol. 8, no. 11, 63. DOI: 10.3390/inorganics8110063}} @misc{smits_firstprinciples_melting_2020, author={Smits, O., Jerabek, P., Pahl, E., Schwerdtfeger, P.}, title={First-principles melting of krypton and xenon based on many-body relativistic coupled-cluster interaction potentials}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1103/PhysRevB.101.104103}, abstract = {The solid-to-liquid phase transition for krypton and xenon is studied by means of parallel-tempering Monte Carlo simulations based on an accurate description of the atomic interactions within a many-body ansatz using relativistic coupled-cluster theory. These high-level data were subsequently fitted to computationally efficient extended Lennard-Jones and extended Axilrod-Teller-Muto types of interaction potentials. Solid-state calculations demonstrate that the many-body decomposition of the interaction energy converges well for the heavier rare gas solids, leading to solid-state properties in good agreement with experiment. The results show that it suffices to include two- and three-body interactions only for the melting simulation. The melting of the bulk is simulated for cells with cubic periodic boundary conditions, as well as within a finite cluster approach. For the latter, melting of spherical magic number clusters with increasing cluster size is studied, and the melting temperatures are obtained from extrapolation to the bulk. The calculated melting temperatures for the cluster extrapolation (the periodic approach values corrected for superheating are set in parentheses) are Tm=113.7 K (110.9 K) and Tm=160.8 K (156.1 K) for krypton and xenon, respectively. Both are in very good agreement with corresponding experimental values of 115.75 and 161.40 K.}, note = {Online available at: \url{https://doi.org/10.1103/PhysRevB.101.104103} (DOI). Smits, O.; Jerabek, P.; Pahl, E.; Schwerdtfeger, P.: First-principles melting of krypton and xenon based on many-body relativistic coupled-cluster interaction potentials. Physical Review B. 2020. vol. 101, no. 10, 104103. DOI: 10.1103/PhysRevB.101.104103}} @misc{smits_oganesson_a_2020, author={Smits, O., Mewes, J., Jerabek, P., Schwerdtfeger, P.}, title={Oganesson: A Noble Gas Element That Is Neither Noble Nor a Gas}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1002/anie.202011976}, abstract = {Oganesson (Og) is the last entry into the Periodic Table completing the seventh period of elements and group 18 of the noble gases. Only three atoms of Og have been successfully produced in nuclear collision experiments, with an estimate half‐life for [[EQUATION]] of [[EQUATION]] ms. [1] With such a short lifetime, chemical and physical properties inevitably have to come from accurate relativistic quantum theory. Here, we employ two complementary computational approaches, namely parallel tempering Monte‐Carlo (PTMC) simulations and first‐principles thermodynamic integration (TI), both calibrated against a highly accurate coupled‐cluster reference to pin‐down the melting and boiling points of this super‐heavy element. In excellent agreement, these approaches show Og to be a solid at ambient conditions with a melting point of ~325 K. In contrast, calculations in the nonrelativistic limit reveal a melting point for Og of 220 K, suggesting a gaseous state as expected for a typical noble gas element. Accordingly, relativistic effects shift the solid‐to‐liquid phase transition by about 100 K.}, note = {Online available at: \url{https://doi.org/10.1002/anie.202011976} (DOI). Smits, O.; Mewes, J.; Jerabek, P.; Schwerdtfeger, P.: Oganesson: A Noble Gas Element That Is Neither Noble Nor a Gas. Angewandte Chemie - International Edition. 2020. vol. 59, no. 52, 23636-23640. DOI: 10.1002/anie.202011976}} @misc{kriegel_chemical_and_2020, author={Kriegel, H., Kollmann, J., Raudsepp, R., Klassen, T., Schieda, M.}, title={Chemical and photoelectrochemical instability of amorphous TiO2 layers quantified by spectroscopic ellipsometry}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1039/D0TA04878J}, abstract = {Amorphous TiO2 films deposited by Atomic Layer Deposition (ALD) are recently being employed as corrosion protection coatings for photoanodes and photocathodes. However, these protective films are not immune to degradation. We have applied spectroscopic ellipsometry to quantify the loss of material, and the corresponding etch rates, for amorphous TiO2 in photoelectrochemical cells under a wide range of conditions, at open- and short-circuit, in darkness and under illumination with different wavelength ranges. In 0.5 M sulfuric acid, we found corrosion to proceed via two routes: a chemical process, with an activation energy of 57 kJ mol−1, and photoelectrochemically, once excess generated charge carriers are extracted. Compared to the dark condition, the combined degradation rate is more than doubled under illumination at 100 mW cm−2 and at pH 0.3–2. The observed etch processes are highly dependent on the acidic pH values and largely suppressed at pH > 4. This has important implications for the selection of operating conditions for practical photoelectrochemical cells using amorphous TiO2 protective coatings.}, note = {Online available at: \url{https://doi.org/10.1039/D0TA04878J} (DOI). Kriegel, H.; Kollmann, J.; Raudsepp, R.; Klassen, T.; Schieda, M.: Chemical and photoelectrochemical instability of amorphous TiO2 layers quantified by spectroscopic ellipsometry. Journal of Materials Chemistry A. 2020. vol. 35, 18173-18179. DOI: 10.1039/D0TA04878J}} @misc{hadjixenophontos_a_review_2020, author={Hadjixenophontos, E., Dematteis, E., Berti, N., Wolczyk, A., Huen, P., Brighi, M., Le, T., Santoru, A., Payandeh, S., Peru, F., Dao, A., Liu, Y., Heere, M.}, title={A Review of the MSCA ITN ECOSTORE—Novel Complex Metal Hydrides for Efficient and Compact Storage of Renewable Energy as Hydrogen and Electricity}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.3390/inorganics8030017}, abstract = {Hydrogen as an energy carrier is very versatile in energy storage applications. Developments in novel, sustainable technologies towards a CO2-free society are needed and the exploration of all-solid-state batteries (ASSBs) as well as solid-state hydrogen storage applications based on metal hydrides can provide solutions for such technologies. However, there are still many technical challenges for both hydrogen storage material and ASSBs related to designing low-cost materials with low-environmental impact. The current materials considered for all-solid-state batteries should have high conductivities for Na+, Mg2+ and Ca2+, while Al3+-based compounds are often marginalised due to the lack of suitable electrode and electrolyte materials. In hydrogen storage materials, the sluggish kinetic behaviour of solid-state hydride materials is one of the key constraints that limit their practical uses. Therefore, it is necessary to overcome the kinetic issues of hydride materials before discussing and considering them on the system level. This review summarizes the achievements of the Marie Skłodowska-Curie Actions (MSCA) innovative training network (ITN) ECOSTORE, the aim of which was the investigation of different aspects of (complex) metal hydride materials. Advances in battery and hydrogen storage materials for the efficient and compact storage of renewable energy production are discussed.}, note = {Online available at: \url{https://doi.org/10.3390/inorganics8030017} (DOI). Hadjixenophontos, E.; Dematteis, E.; Berti, N.; Wolczyk, A.; Huen, P.; Brighi, M.; Le, T.; Santoru, A.; Payandeh, S.; Peru, F.; Dao, A.; Liu, Y.; Heere, M.: A Review of the MSCA ITN ECOSTORE—Novel Complex Metal Hydrides for Efficient and Compact Storage of Renewable Energy as Hydrogen and Electricity. Inorganics. 2020. vol. 8, no. 3, 17. DOI: 10.3390/inorganics8030017}} @misc{gizer_improved_kinetic_2020, author={Gizer, G., Puszkiel, J., Riglos, M., Pistidda, C., Ramallo-López, J., Mizrahi, M., Santoru, A., Gemming, T., Tseng, J., Klassen, T., Dornheim, M.}, title={Improved kinetic behaviour of Mg(NH2)2-2LiH doped with nanostructured K-modified-LixTiyOz for hydrogen storage}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1038/s41598-019-55770-y}, abstract = {The system Mg(NH2)2 + 2LiH is considered as an interesting solid-state hydrogen storage material owing to its low thermodynamic stability of ca. 40 kJ/mol H2 and high gravimetric hydrogen capacity of 5.6 wt.%. However, high kinetic barriers lead to slow absorption/desorption rates even at relatively high temperatures (>180 °C). In this work, we investigate the effects of the addition of K-modified LixTiyOz on the absorption/desorption behaviour of the Mg(NH2)2 + 2LiH system. In comparison with the pristine Mg(NH2)2 + 2LiH, the system containing a tiny amount of nanostructured K-modified LixTiyOz shows enhanced absorption/desorption behaviour. The doped material presents a sensibly reduced (∼30 °C) desorption onset temperature, notably shorter hydrogen absorption/desorption times and reversible hydrogen capacity of about 3 wt.% H2 upon cycling. Studies on the absorption/desorption processes and micro/nanostructural characterizations of the Mg(NH2)2 + 2LiH + K-modified LixTiyOz system hint to the fact that the presence of in situ formed nanostructure K2TiO3 is the main responsible for the observed improved kinetic behaviour.}, note = {Online available at: \url{https://doi.org/10.1038/s41598-019-55770-y} (DOI). Gizer, G.; Puszkiel, J.; Riglos, M.; Pistidda, C.; Ramallo-López, J.; Mizrahi, M.; Santoru, A.; Gemming, T.; Tseng, J.; Klassen, T.; Dornheim, M.: Improved kinetic behaviour of Mg(NH2)2-2LiH doped with nanostructured K-modified-LixTiyOz for hydrogen storage. Scientific Reports. 2020. vol. 10, 8. DOI: 10.1038/s41598-019-55770-y}} @misc{le_enhanced_stability_2020, author={Le, T.-T., Pistidda, C., Abetz, C., Georgopanos, P., Garroni, S., Capurso, G., Milanese, C., Puszkiel, J., Dornheim, M., Abetz, V., Klassen, T.}, title={Enhanced Stability of Li-RHC Embedded in an Adaptive TPX™ Polymer Scaffold}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.3390/ma13040991}, abstract = {In this work, the possibility of creating a polymer-based adaptive scaffold for improving the hydrogen storage properties of the system 2LiH+MgB2+7.5(3TiCl3·AlCl3) was studied. Because of its chemical stability toward the hydrogen storage material, poly(4-methyl-1-pentene) or in-short TPXTM was chosen as the candidate for the scaffolding structure. The composite system was obtained after ball milling of 2LiH+MgB2+7.5(3TiCl3·AlCl3) and a solution of TPXTM in cyclohexane. The investigations carried out over the span of ten hydrogenation/de-hydrogenation cycles indicate that the material containing TPXTM possesses a higher degree of hydrogen storage stability.}, note = {Online available at: \url{https://doi.org/10.3390/ma13040991} (DOI). Le, T.; Pistidda, C.; Abetz, C.; Georgopanos, P.; Garroni, S.; Capurso, G.; Milanese, C.; Puszkiel, J.; Dornheim, M.; Abetz, V.; Klassen, T.: Enhanced Stability of Li-RHC Embedded in an Adaptive TPX™ Polymer Scaffold. Materials. 2020. vol. 13, no. 4, 991. DOI: 10.3390/ma13040991}} @misc{bondi_quantitative_and_2020, author={Bondi, L., Garden, A., Jerabek, P., Totti, F., Brooker, S.}, title={Quantitative and Chemically Intuitive Evaluation of the Nature of M−L Bonds in Paramagnetic Compounds: Application of EDA‐NOCV Theory to Spin Crossover Complexes}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1002/chem.202002146}, abstract = {With the aim of improving understanding of M‐L bonds in 3d transition metal complexes, quantitative analysis by Energy Decomposition Analysis and Natural Orbital for Chemical Valence model (EDA‐NOCV) is done on octahedral spin crossover (SCO) complexes, as the transition temperature (T1/2) is sensitive to subtle changes in M‐L bonding. EDA‐NOCV analysis of Fe‐N bonds in 5 [FeII( Lazine )2(NCBH3)2], in both low spin (LS) and paramagnetic high spin (HS) states, led to (a) development of a general, widely applicable, corrected M+L6 fragmentation, tested against a family of 5 LS [FeII( Lazine )3(BF4)2], confirming that 3 Lazine are stronger ligands (ΔEorb,σ+π ≈ ‐370 kcal/mol) than 2 Lazine + 2 NCBH3 (≈ ‐335 kcal/mol), as observed; (b) analysis of Fe‐L bonding on LS → HS, reveals more ionic (ΔEelstat) and less covalent (ΔEorb) character (ΔEelstat:ΔEorb 55:45 LS → 64:36 HS), mostly due to a big drop in σ‐ (ΔEorb,σ ↓50%; ‐310 → ‐145 kcal/mol), and a drop in π‐ contributions (ΔEorb,π ↓90%; ‐30 → ‐3 kcal/mol); (c) strong correlation of observed T1/2 and ΔEorb,σ+π, for both LS and HS families (R2 =0.99 LS, R2 = 0.95 HS), but no correlation of T1/2 and ΔΔEorb,σ+π(LS‐HS) (R2 =0.11). Overall, this study has established and validated a generally applicable fragmentation and computational protocol for EDA‐NOCV M‐L bonding analysis of any diamagnetic or paramagnetic, homoleptic or heteroleptic, octahedral transition metal complex.}, note = {Online available at: \url{https://doi.org/10.1002/chem.202002146} (DOI). Bondi, L.; Garden, A.; Jerabek, P.; Totti, F.; Brooker, S.: Quantitative and Chemically Intuitive Evaluation of the Nature of M−L Bonds in Paramagnetic Compounds: Application of EDA‐NOCV Theory to Spin Crossover Complexes. Chemistry - A European Journal. 2020. vol. 26, no. 60, 13677-13685. DOI: 10.1002/chem.202002146}} @misc{hirscher_materials_for_2020, author={Hirscher, M., Yartys, V.A., Baricco, M., Bellosta von Colbe, J., Blanchard, D., Bowman, R.C., Jr., Broom, D.P., Buckley, C.E., Chang, F., Chen, P., Cho, Y.W., Crivello, J.-C., Cuevas, F., David, W.I.F., de Jongh, P.E., Denys, R.V., Dornheim, M., Felderhoff, M., Filinchuk, Y., Froudakis, G.E., Grant, D.M., Gray, E.M., Hauback, B.C., He, T., Humphries, T.D., Jensen, T.R., Kim, S., Kojima, Y., Latroche, M., Li, H.-W., Lototskyy, M.V., Makepeace, J.W., Møller, K.T., Naheed, L., Ngene, P., Noréus, D., Nygård, M.M., Orimo, S.-I., Paskevicius, M., Pasquini, L., Ravnsbæk, D.B., Veronica Sofianos, M., Udovic, T.J., Vegge, T., Walker, G.S., Webb, C.J., Weidenthaler, C., Zlotea, C.}, title={Materials for hydrogen-based energy storage – past, recent progress and future outlook}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2019.153548}, abstract = {Globally, the accelerating use of renewable energy sources, enabled by increased efficiencies and reduced costs, and driven by the need to mitigate the effects of climate change, has significantly increased research in the areas of renewable energy production, storage, distribution and end-use. Central to this discussion is the use of hydrogen, as a clean, efficient energy vector for energy storage. This review, by experts of Task 32, “Hydrogen-based Energy Storage” of the International Energy Agency, Hydrogen TCP, reports on the development over the last 6 years of hydrogen storage materials, methods and techniques, including electrochemical and thermal storage systems. An overview is given on the background to the various methods, the current state of development and the future prospects. The following areas are covered; porous materials, liquid hydrogen carriers, complex hydrides, intermetallic hydrides, electrochemical storage of energy, thermal energy storage, hydrogen energy systems and an outlook is presented for future prospects and research on hydrogen-based energy storage.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2019.153548} (DOI). Hirscher, M.; Yartys, V.; Baricco, M.; Bellosta von Colbe, J.; Blanchard, D.; Bowman, R.; Jr.; Broom, D.; Buckley, C.; Chang, F.; Chen, P.; Cho, Y.; Crivello, J.; Cuevas, F.; David, W.; de Jongh, P.; Denys, R.; Dornheim, M.; Felderhoff, M.; Filinchuk, Y.; Froudakis, G.; Grant, D.; Gray, E.; Hauback, B.; He, T.; Humphries, T.; Jensen, T.; Kim, S.; Kojima, Y.; Latroche, M.; Li, H.; Lototskyy, M.; Makepeace, J.; Møller, K.; Naheed, L.; Ngene, P.; Noréus, D.; Nygård, M.; Orimo, S.; Paskevicius, M.; Pasquini, L.; Ravnsbæk, D.; Veronica Sofianos, M.; Udovic, T.; Vegge, T.; Walker, G.; Webb, C.; Weidenthaler, C.; Zlotea, C.: Materials for hydrogen-based energy storage – past, recent progress and future outlook. Journal of Alloys and Compounds. 2020. vol. 827, 153548. DOI: 10.1016/j.jallcom.2019.153548}} @misc{heere_dynamics_of_2020, author={Heere, M., Hansen, A.-L., Payandeh, S.H., Aslan, N., Gizer, G., Sørby, M.H., Hauback, B.C., Pistidda, C., Dornheim, M., Lohstroh, W.}, title={Dynamics of porous and amorphous magnesium borohydride to understand solid state Mg-ion-conductors}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1038/s41598-020-65857-6}, abstract = {Rechargeable solid-state magnesium batteries are considered for high energy density storage and usage in mobile applications as well as to store energy from intermittent energy sources, triggering intense research for suitable electrode and electrolyte materials. Recently, magnesium borohydride, Mg(BH4)2, was found to be an effective precursor for solid-state Mg-ion conductors. During the mechanochemical synthesis of these Mg-ion conductors, amorphous Mg(BH4)2 is typically formed and it was postulated that this amorphous phase promotes the conductivity. Here, electrochemical impedance spectroscopy of as-received γ-Mg(BH4)2 and ball milled, amorphous Mg(BH4)2 confirmed that the conductivity of the latter is ~2 orders of magnitude higher than in as-received γ-Mg(BH4)2 at 353 K. Pair distribution function (PDF) analysis of the local structure shows striking similarities up to a length scale of 5.1 Å, suggesting similar conduction pathways in both the crystalline and amorphous sample. Up to 12.27 Å the PDF indicates that a 3D net of interpenetrating channels might still be present in the amorphous phase although less ordered compared to the as-received γ-phase. However, quasi elastic neutron scattering experiments (QENS) were used to study the rotational mobility of the [BH4] units, revealing a much larger fraction of activated [BH4] rotations in amorphous Mg(BH4)2. These findings suggest that the conduction process in amorphous Mg(BH4)2 is supported by stronger rotational mobility, which is proposed to be the so-called “paddle-wheel” mechanism.}, note = {Online available at: \url{https://doi.org/10.1038/s41598-020-65857-6} (DOI). Heere, M.; Hansen, A.; Payandeh, S.; Aslan, N.; Gizer, G.; Sørby, M.; Hauback, B.; Pistidda, C.; Dornheim, M.; Lohstroh, W.: Dynamics of porous and amorphous magnesium borohydride to understand solid state Mg-ion-conductors. Scientific Reports. 2020. vol. 10, no. 1, 9080. DOI: 10.1038/s41598-020-65857-6}} @misc{shang_conductive_and_2020, author={Shang, G., Dyachenko, P., Leib, E.W., Vossmeyer, T., Petrov, A., Eich, M.}, title={Conductive and radiative heat transfer inhibition in YSZ photonic glass}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ceramint.2020.04.262}, abstract = {A high temperature stable ceramic photonic structure is demonstrated with low thermal conductivity and suppressed external radiative heat transfer. The structure is based on a disordered arrangement of yttria-stabilized zirconia (YSZ) microparticles, called photonic glass (PhG). The prepared YSZ-PhG film exhibits low thermal conductivity of 0.03 Wm−1K−1 comparable to that of the air. The small point contacts of the adjacent YSZ particles are the main cause of such low thermal conductivity. After annealing at 1400 °C for 5 h, the solid thermal conductivity increased to 0.3 Wm−1K−1 at room temperature due to the thermally induced neck formation, associated with an increased contact area between adjacent particles. This thermal conductivity is still much lower than that of conventional YSZ thermal barrier coatings (TBCs) with approximately 1 Wm−1K−1. At the same time, the PhG structure is an efficient scatterer for thermal radiation in the wavelength range between 1 and 6 μm. In an only 100 μm thick structure an average reflection of 84% was obtained. At 1400 °C, the effective thermal conductivity is 0.2 Wm−1K−1. The presented structure is applicable to other oxides with even lower bulk thermal conductivity and can be considered for future TBCs.}, note = {Online available at: \url{https://doi.org/10.1016/j.ceramint.2020.04.262} (DOI). Shang, G.; Dyachenko, P.; Leib, E.; Vossmeyer, T.; Petrov, A.; Eich, M.: Conductive and radiative heat transfer inhibition in YSZ photonic glass. Ceramics International. 2020. vol. 46, no. 11, 19241-19247. DOI: 10.1016/j.ceramint.2020.04.262}} @misc{shang_surface_templated_2020, author={Shang, G., Furlan, K.P., Janßen, R., Petrov, A., Eich, M.}, title={Surface templated inverse photonic glass for saturated blue structural color}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1364/OE.380488}, abstract = {To substitute conventional pigments, which often are toxic or suffer from fading in ultraviolet light, non-iridescent structural colors should demonstrate high spectral selectivity, while being also mechanically stable. However, conventional photonic glass (PhG) shows low color saturation due to the gradual transition in the reflection spectrum and low mechanical stability due to weak interparticle attachment. Here, a PhG with sharp spectral transition in comparison with the conventional full sphere PhG is designed by a conformal coating via atomic layer deposition (ALD) onto an organic PhG template. The ALD deposition allows to control the film thickness precisely for the highly saturated color. This structure can be described by hollow particle motifs with the effective size larger than the interparticle distance. Such unusual PhG is motivated by the achievable features in the spatial Fourier transform of a disordered assembly of such motifs. The surface-templated inverse PhG shows much higher color saturation than the direct PhG from full spheres. Moreover, the dense and solid connected shell will be beneficial for mechanical stability. These results pave the way for highly saturated structural colors. The demonstrated sharp spectral selection feature can be also considered for many related applications such as sunscreens, photovoltaics and radiative cooling by adjusting the reflection transition to the required wavelength. This can be achieved by proportionally scaling the motif and lattice dimensions as well as the film thickness.}, note = {Online available at: \url{https://doi.org/10.1364/OE.380488} (DOI). Shang, G.; Furlan, K.; Janßen, R.; Petrov, A.; Eich, M.: Surface templated inverse photonic glass for saturated blue structural color. Optics Express. 2020. vol. 28, no. 6, 7759-7770. DOI: 10.1364/OE.380488}} @misc{rodio_experimental_evidence_2020, author={Rodio, M., Graf, M., Schulz, F., Mueller, N.S., Eich, M., Lange, H.}, title={Experimental Evidence for Nonthermal Contributions to Plasmon-Enhanced Electrochemical Oxidation Reactions}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acscatal.9b05401}, abstract = {Photocatalysis based on plasmonic nanoparticles has emerged as a promising approach to facilitate light-driven reactions under far milder conditions than thermal catalysis. Several effects, such as strong local electromagnetic fields, increased electron and lattice temperatures, or the transfer of nonthermal charge carriers, could contribute to the reaction rate enhancement. In order to understand plasmon-enhanced catalysis and to enable plasmonic platforms, a distinction between the different underlying effects is required. We investigate the electrochemical model reactions oxidative hydroxide adsorption and glucose oxidation and deconvolve the enhancement processes via their dependence on the excitation wavelength. We observe that nonthermal effects contribute significantly to the plasmonic enhancement.}, note = {Online available at: \url{https://doi.org/10.1021/acscatal.9b05401} (DOI). Rodio, M.; Graf, M.; Schulz, F.; Mueller, N.; Eich, M.; Lange, H.: Experimental Evidence for Nonthermal Contributions to Plasmon-Enhanced Electrochemical Oxidation Reactions. ACS Catalysis. 2020. vol. 10, no. 3, 2345-2353. DOI: 10.1021/acscatal.9b05401}} @misc{gaafar_pulse_time_2020, author={Gaafar, M.A., Holtorf, J., Eich, M., Petrov, A.Yu.}, title={Pulse time reversal and stopping by a refractive index front}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1063/5.0007986}, abstract = {We discuss how dynamic light stopping and pulse time reversal can be implemented in dispersive waveguides via indirect photonic transitions induced by moving refractive index fronts. The previous concepts of light stopping/time reversal either require complex local variation of the device’s refractive index or rely on the strict phase matching condition, which imposes limitations on the amount of manipulated information. Until now, only single pulses or continuous waves were manipulated experimentally. Our scheme is not limited by a strict phase matching condition and does not require local index variations, thus it can manipulate broadband signals in a single step process. Here, we present several numerically integrated results for pulse time reversal and stopping/storage via indirect front-induced transitions. The presented results are experimentally feasible using existing photonic waveguide technologies.}, note = {Online available at: \url{https://doi.org/10.1063/5.0007986} (DOI). Gaafar, M.; Holtorf, J.; Eich, M.; Petrov, A.: Pulse time reversal and stopping by a refractive index front. APL Photonics. 2020. vol. 5, no. 8, 080801. DOI: 10.1063/5.0007986}} @misc{shang_photonic_glass_2020, author={Shang, G., Eich, M., Petrov, A.}, title={Photonic glass based structural color}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1063/5.0006203}, abstract = {Structural coloration, which is based on spectrally selective scattering from optical structures, has recently attracted wide attention as a replacement of pigment colors based on the selective light absorption in chemical structures. Structural colors can be produced from transparent non-toxic materials and provide high stability under solar radiation. To provide angle independent non-iridescent colors, the structure should combine spectral selectivity with an isotropic response. Photonic glass (PhG), a disordered arrangement of monodisperse spheres, is a versatile structure to achieve that, which provides isotropic spectral selectivity via short-range order and Mie resonances. However, conventional PhGs show low color purity that hinders their future application. The interplay of single-particle scattering, short-range order, broadband absorption, and Fresnel reflection is a route to improve the color. In this perspective, we review the field of PhG based structural colors and discuss the physical mechanism behind the color generation by several established theories. We point out the current challenges in the theory and possible directions to improve color purity.}, note = {Online available at: \url{https://doi.org/10.1063/5.0006203} (DOI). Shang, G.; Eich, M.; Petrov, A.: Photonic glass based structural color. APL Photonics. 2020. vol. 5, no. 6, 060901. DOI: 10.1063/5.0006203}} @misc{puszkiel_designing_an_2020, author={Puszkiel, J., Bellosta von Colbe, J.M., Jepsen, J., Mitrokhin, S.V., Movlaev, E., Verbetsky, V., Klassen, T.}, title={Designing an AB2-Type Alloy (TiZr-CrMnMo) for the Hybrid Hydrogen Storage Concept}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.3390/en13112751}, abstract = {The hybrid hydrogen storage method consists of the combination of both solid-state metal hydrides and gas hydrogen storage. This method is regarded as a promising trade-off solution between the already developed high-pressure storage reservoir, utilized in the automobile industry, and solid-state storage through the formation of metal hydrides. Therefore, it is possible to lower the hydrogen pressure and to increase the hydrogen volumetric density. In this work, we design a non-stoichiometric AB2 C14-Laves alloy composed of (Ti0.9Zr0.1)1.25Cr0.85Mn1.1Mo0.05. This alloy is synthesized by arc-melting, and the thermodynamic and kinetic behaviors are evaluated in a high-pressure Sieverts apparatus. Proper thermodynamic parameters are obtained in the range of temperature and pressure from 3 to 85 °C and from 15 to 500 bar: ΔHabs. = 22 ± 1 kJ/mol H2, ΔSabs. = 107 ± 2 J/K mol H2, and ΔHdes. = 24 ± 1 kJ/mol H2, ΔSdes. = 110 ± 3 J/K mol H2. The addition of 10 wt.% of expanded natural graphite (ENG) allows the improvement of the heat transfer properties, showing a reversible capacity of about 1.5 wt.%, cycling stability and hydrogenation/dehydrogenation times between 25 to 70 s. The feasibility for the utilization of the designed material in a high-pressure tank is also evaluated, considering practical design parameters.}, note = {Online available at: \url{https://doi.org/10.3390/en13112751} (DOI). Puszkiel, J.; Bellosta von Colbe, J.; Jepsen, J.; Mitrokhin, S.; Movlaev, E.; Verbetsky, V.; Klassen, T.: Designing an AB2-Type Alloy (TiZr-CrMnMo) for the Hybrid Hydrogen Storage Concept. Energies. 2020. vol. 13, no. 11, 2751. DOI: 10.3390/en13112751}} @misc{bellostavoncolbe_scaleup_of_2019, author={Bellosta von Colbe, J.M., Puszkiel, J., Capurso, G., Franz, A., Benz, H.U., Zoz, H., Klassen, T., Dornheim, M.}, title={Scale-up of milling in a 100 L device for processing of TiFeMn alloy for hydrogen storage applications: Procedure and characterization}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2019.01.174}, abstract = {In this work, the mechanical milling of a FeTiMn alloy for hydrogen storage purposes was performed in an industrial milling device. The TiFe hydride is interesting from the technological standpoint because of the abundance and the low cost of its constituent elements Ti and Fe, as well as its high volumetric hydrogen capacity. However, TiFe is difficult to activate, usually requiring a thermal treatment above 400 °C. A TiFeMn alloy milled for just 10 min in a 100 L industrial milling device showed excellent hydrogen storage properties without any thermal treatment. The as-milled TiFeMn alloy did not need any activation procedure and showed fast kinetic behavior and good cycling stability. Microstructural and morphological characterization of the as-received and as-milled TiFeMn alloys revealed that the material presents reduced particle and crystallite sizes, even after such short time of milling. The refined microstructure of the as-milled TiFeMn is deemed to account for the improved hydrogen absorption-desorption properties.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2019.01.174} (DOI). Bellosta von Colbe, J.; Puszkiel, J.; Capurso, G.; Franz, A.; Benz, H.; Zoz, H.; Klassen, T.; Dornheim, M.: Scale-up of milling in a 100 L device for processing of TiFeMn alloy for hydrogen storage applications: Procedure and characterization. International Journal of Hydrogen Energy. 2019. vol. 44, no. 55, 29282-29290. DOI: 10.1016/j.ijhydene.2019.01.174}} @misc{jepsen_effect_of_2019, author={Jepsen, J., Capurso, G., Puszkiel, J., Busch, N., Werner, T., Milanese, C., Girella, A., Bellosta von Colbe, J., Dornheim, M., Klassen, T.}, title={Effect of the Process Parameters on the Energy Transfer during the Synthesis of the 2LiBH4-MgH2 Reactive Hydride Composite for Hydrogen Storage}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.3390/met9030349}, abstract = {Several different milling parameters (additive content, rotation velocity, ball-to-powder ratio, degree of filling, and time) affect the hydrogen absorption and desorption properties of a reactive hydride composite (RHC). In this paper, these effects were thoroughly tested and analyzed. The milling process investigated in such detail was performed on the 2LiH-MgB2 system doped with TiCl3. Applying an upgraded empirical model, the transfer of energy to the material during the milling process was determined. In this way, it is possible to compare the obtained experimental results with those from processes at different scales. In addition, the different milling parameters were evaluated independently according to their individual effect on the transferred energy. Their influence on the reaction kinetics and hydrogen capacity was discussed and the results were correlated to characteristics like particle and crystallite size, specific surface area, presence of nucleation sites and contaminants. Finally, an optimal value for the transferred energy was determined, above which the powder characteristics do not change and therefore the RHC system properties do not further improve.}, note = {Online available at: \url{https://doi.org/10.3390/met9030349} (DOI). Jepsen, J.; Capurso, G.; Puszkiel, J.; Busch, N.; Werner, T.; Milanese, C.; Girella, A.; Bellosta von Colbe, J.; Dornheim, M.; Klassen, T.: Effect of the Process Parameters on the Energy Transfer during the Synthesis of the 2LiBH4-MgH2 Reactive Hydride Composite for Hydrogen Storage. Metals. 2019. vol. 9, no. 3, 349. DOI: 10.3390/met9030349}} @misc{gaafar_frontinduced_transitions_2019, author={Gaafar, M.A., Baba, T., Eich, M., Petrov, A.Y.}, title={Front-induced transitions}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1038/s41566-019-0511-6}, abstract = {Refractive index fronts propagating in waveguides are special spatiotemporal perturbations. The interaction of light with such fronts can be described in terms of an indirect transition where the frequency and wavenumber of a guided mode both are changed. In recent years, front-induced transitions have been used in dispersion-engineered waveguides for frequency conversion, optical delays, and bandwidth and pulse duration manipulation. These concepts have originated from different research areas of photonics, such as nonlinear fibre optics, slow-light waveguides, plasma physics, moving media and relativistic effects. Here, we discuss these concepts, providing a unifying theoretical description and highlight the potential of this exciting research field for light manipulation in guided optics.}, note = {Online available at: \url{https://doi.org/10.1038/s41566-019-0511-6} (DOI). Gaafar, M.; Baba, T.; Eich, M.; Petrov, A.: Front-induced transitions. Nature Photonics. 2019. vol. 13, no. 11, 737-748. DOI: 10.1038/s41566-019-0511-6}} @misc{gizer_tuning_the_2019, author={Gizer, G., Puszkiel, J., Cao, H., Pistidda, C., Le, T., Dornheim, M., Klassen, T.}, title={Tuning the reaction mechanism and hydrogenation/dehydrogenation properties of 6Mg(NH2)2single bond9LiH system by adding LiBH4}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2019.03.133}, abstract = {The hydrogen storage properties of 6Mg(NH2)2single bond9LiH-x(LiBH4) (x = 0, 0.5, 1, 2) system and the role of LiBH4 on the kinetic behaviour and the dehydrogenation/hydrogenation reaction mechanism were herein systematically investigated. Among the studied compositions, 6Mg(NH2)2single bond9LiHsingle bond2LiBH4 showed the best hydrogen storage properties. The presence of 2 mol of LiBH4 improved the thermal behaviour of the 6Mg(NH2)2single bond9LiH by lowering the dehydrogenation peak temperature nearly 25 °C and by reducing the apparent dehydrogenation activation energy of about 40 kJ/mol. Furthermore, this material exhibited fast dehydrogenation (10 min) and hydrogenation kinetics (3 min) and excellent cycling stability with a reversible hydrogen capacity of 3.5 wt % at isothermal 180 °C. Investigations on the reaction pathway indicated that the observed superior kinetic behaviour likely related to the formation of Li4(BH4)(NH2)3. Studies on the rate-limiting steps hinted that the sluggish kinetic behaviour of the 6Mg(NH2)2single bond9LiH pristine material are attributed to an interface-controlled mechanism. On the contrary, LiBH4-containing samples show a diffusion-controlled mechanism. During the first dehydrogenation reaction, the possible formation of Li4(BH4)(NH2)3 accelerates the reaction rates at the interface. Upon hydrogenation, this ‘liquid like’ of Li4(BH4)(NH2)3 phase assists the diffusion of small ions into the interfaces of the amide-hydride matrix.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2019.03.133} (DOI). Gizer, G.; Puszkiel, J.; Cao, H.; Pistidda, C.; Le, T.; Dornheim, M.; Klassen, T.: Tuning the reaction mechanism and hydrogenation/dehydrogenation properties of 6Mg(NH2)2single bond9LiH system by adding LiBH4. International Journal of Hydrogen Energy. 2019. vol. 44, no. 23, 11920-11929. DOI: 10.1016/j.ijhydene.2019.03.133}} @misc{gizer_enhancement_effect_2019, author={Gizer, G., Cao, H., Puszkiel, J., Pistidda, C., Santoru, A., Zhang, W., He, T., Chen, P., Klassen, T., Dornheim, M.}, title={Enhancement Effect of Bimetallic Amide K2Mn(NH2)4 and In-Situ Formed KH and Mn4N on the Dehydrogenation/Hydrogenation Properties of Li–Mg–N–H System}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.3390/en12142779}, abstract = {In this work, we investigated the influence of the K2Mn(NH2)4 additive on the hydrogen sorption properties of the Mg(NH2)2 + 2LiH (Li–Mg–N–H) system. The addition of 5 mol% of K2Mn(NH2)4 to the Li–Mg–N–H system leads to a decrease of the dehydrogenation peak temperature from 200 °C to 172 °C compared to the pristine sample. This sample exhibits a constant hydrogen storage capacity of 4.2 wt.% over 25 dehydrogenation/rehydrogenation cycles. Besides that, the in-situ synchrotron powder X-ray diffraction analysis performed on the as prepared Mg(NH2)2 + 2LiH containing K2Mn(NH2)4 indicates the presence of Mn4N. However, no crystalline K-containing phases were detected. Upon dehydrogenation, the formation of KH is observed. The presence of KH and Mn4N positively influences the hydrogen sorption properties of this system, especially at the later stage of rehydrogenation. Under the applied conditions, hydrogenation of the last 1 wt.% takes place in only 2 min. This feature is preserved in the following three cycles.}, note = {Online available at: \url{https://doi.org/10.3390/en12142779} (DOI). Gizer, G.; Cao, H.; Puszkiel, J.; Pistidda, C.; Santoru, A.; Zhang, W.; He, T.; Chen, P.; Klassen, T.; Dornheim, M.: Enhancement Effect of Bimetallic Amide K2Mn(NH2)4 and In-Situ Formed KH and Mn4N on the Dehydrogenation/Hydrogenation Properties of Li–Mg–N–H System. Energies. 2019. vol. 12, no. 14, 2779. DOI: 10.3390/en12142779}} @misc{fohrmann_freecarrier_detection_2019, author={Fohrmann, L.S., Lotfi, N., Alzein, B., Gaafar, M.A., Petrov, A.Y.U., Eich, M.}, title={Free-carrier detection in a silicon slab via absorption measurement in 2D integrating cells}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1364/OL.44.000175}, abstract = {2D integrating cells provide long optical path lengths on a chip by multiple reflections at highly reflective mirrors similar to integrating spheres in free space. Therefore, they build a promising platform for integrated optical absorption sensing. Here, we present first absorption measurements of free carriers generated by a modulated pump laser inside a 2D integrating cell in a silicon slab. The results can be used to evaluate the lifetimes of free carriers in silicon slabs for integrated optics. Employing a silicon-on-insulator platform with a silicon thickness of 220 nm, we demonstrate measurements of the access free-carrier concentration on the order of 1−8·1015 cm−3 with lifetimes on the order of 0.1–1 μs governed by surface recombination at the silicon interfaces. The measured lifetimes are dependent on free-carrier concentration, which confirms previous observations. The presented free-carrier absorption experiment verifies the sensitivity of 2D integrating cells to changes in the absorption coefficient and thus demonstrates the potential of 2D integrating cells for absorption sensing.}, note = {Online available at: \url{https://doi.org/10.1364/OL.44.000175} (DOI). Fohrmann, L.; Lotfi, N.; Alzein, B.; Gaafar, M.; Petrov, A.; Eich, M.: Free-carrier detection in a silicon slab via absorption measurement in 2D integrating cells. Optics Letters. 2019. vol. 44, no. 1, 175-178. DOI: 10.1364/OL.44.000175}} @misc{gaafar_linear_schrdinger_2019, author={Gaafar, M.A., Renner, H., Petrov, A.Y.U., Eich, M.}, title={Linear Schrödinger equation with temporal evolution for front induced transitions}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1364/OE.27.021273}, abstract = {The nonlinear Schrödinger equation based on slowly varying approximation is usually applied to describe the pulse propagation in nonlinear waveguides. However, for the case of the front induced transitions (FITs), the pump effect is well described by the dielectric constant perturbation in space and time. Thus, a linear Schrödinger equation (LSE) can be used. Also, in waveguides with weak dispersion the spatial evolution of the pulse temporal profile is usually tracked. Such a formulation becomes impossible for optical systems for which the group index or higher dispersion terms diverge as is the case near the band edge of photonic crystals. For the description of FITs in such systems a linear Schrödinger equation can be used where temporal evolution of the pulse spatial profile is tracked instead of tracking the spatial evolution. This representation provides the same descriptive power and can easily deal with zero group velocities. Furthermore, the Schrödinger equation with temporal evolution can describe signal pulse reflection from both static and counter-propagating fronts, in contrast to the Schrödinger equation with spatial evolution which is bound to forward propagation. Here, we discuss the two approaches and apply the LSE with temporal evolution for systems close to the band edge where the group velocity vanishes by simulating intraband indirect photonic transitions. We also compare the numerical results with the theoretical predictions from the phase continuity criterion for complete transitions.}, note = {Online available at: \url{https://doi.org/10.1364/OE.27.021273} (DOI). Gaafar, M.; Renner, H.; Petrov, A.; Eich, M.: Linear Schrödinger equation with temporal evolution for front induced transitions. Optics Express. 2019. vol. 27, no. 15, 21273-21284. DOI: 10.1364/OE.27.021273}} @misc{le_efficient_synthesis_2019, author={Le, T., Pistidda, C., Puszkiel, J., Milanese, C., Garroni, S., Emmler, T., Capurso, G., Gizer, G., Klassen, T., Dornheim, M.}, title={Efficient Synthesis of Alkali Borohydrides from Mechanochemical Reduction of Borates Using Magnesium–Aluminum-Based Waste}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.3390/met9101061}, abstract = {Lithium borohydride (LiBH4) and sodium borohydride (NaBH4) were synthesized via mechanical milling of LiBO2, and NaBO2 with Mg–Al-based waste under controlled gaseous atmosphere conditions. Following this approach, the results herein presented indicate that LiBH4 and NaBH4 can be formed with a high conversion yield starting from the anhydrous borates under 70 bar H2. Interestingly, NaBH4 can also be obtained with a high conversion yield by milling NaBO2·4H2O and Mg–Al-based waste under an argon atmosphere. Under optimized molar ratios of the starting materials and milling parameters, NaBH4 and LiBH4 were obtained with conversion ratios higher than 99.5%. Based on the collected experimental results, the influence of the milling energy and the correlation with the final yields were also discussed.}, note = {Online available at: \url{https://doi.org/10.3390/met9101061} (DOI). Le, T.; Pistidda, C.; Puszkiel, J.; Milanese, C.; Garroni, S.; Emmler, T.; Capurso, G.; Gizer, G.; Klassen, T.; Dornheim, M.: Efficient Synthesis of Alkali Borohydrides from Mechanochemical Reduction of Borates Using Magnesium–Aluminum-Based Waste. Metals. 2019. vol. 9, no. 10, 1061. DOI: 10.3390/met9101061}} @misc{bellostavoncolbe_application_of_2019, author={Bellosta von Colbe, J., Ares, J.-R., Barale, J., Baricco, M., Buckley, C., Capurso, G., Gallandat, N., Grant, D.M., Guzik, M.N., Jacob, I., Jensen, E.H., Jensen, T., Jepsen, J., Klassen, T., Lototskyy, M.V., Manickam, K., Montone, A., Puszkiel, J., Sartori, S., Sheppard, D.A., Stuart, A., Walker, G., Webb, C.J., Yang, H., Yartys, V., Zuettel, A., Dornheim, M.}, title={Application of hydrides in hydrogen storage and compression: Achievements, outlook and perspectives}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2019.01.104}, abstract = {In the frame of the “Hydrogen Storage Systems for Mobile and Stationary Applications” Group in the International Energy Agency (IEA) Hydrogen Task 32 “Hydrogen-based energy storage”, different compounds have been and will be scaled-up in the near future and tested in the range of 500 g to several hundred kg for use in hydrogen storage applications.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2019.01.104} (DOI). Bellosta von Colbe, J.; Ares, J.; Barale, J.; Baricco, M.; Buckley, C.; Capurso, G.; Gallandat, N.; Grant, D.; Guzik, M.; Jacob, I.; Jensen, E.; Jensen, T.; Jepsen, J.; Klassen, T.; Lototskyy, M.; Manickam, K.; Montone, A.; Puszkiel, J.; Sartori, S.; Sheppard, D.; Stuart, A.; Walker, G.; Webb, C.; Yang, H.; Yartys, V.; Zuettel, A.; Dornheim, M.: Application of hydrides in hydrogen storage and compression: Achievements, outlook and perspectives. International Journal of Hydrogen Energy. 2019. vol. 44, no. 15, 7780-DOI: 10.1016/j.ijhydene.2019.01.104}} @misc{shang_highly_selective_2019, author={Shang, G., Häntsch, Y., Furlan, K.P., Janßen, R., Schneider, G.A., Petrov, A., Eich, M.}, title={Highly selective photonic glass filter for saturated blue structural color}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1063/1.5084138}, abstract = {Angle independent non-absorbing spectral filters are required for many applications such as sunscreens, structural colors, photovoltaics, and radiative cooling. One of the promising and simple to manufacture structures is based on the disordered arrangement of monodisperse spherical particles by self-assembly, also called photonic glasses. So far, reported photonic glasses inherently show poor spectral selectivity with a smooth transition in reflection. No significant improvement is usually expected from particles optimization as the Mie resonances are broad for small dielectric particles with a moderate refractive index. Via Fourier space engineering, we show here that it is, nonetheless, possible to obtain sharp spectral transitions from the synergetic effect of a core-shell geometry of the particles with the short range order of the photonic glass. We apply the developed approach to demonstrate a high color saturation of a non-iridescent blue structural color employing a photonic glass with hollow sphere particles, which features a sharp spectral transition in reflection. The experimental results support the theoretical predictions from the first-order approximation.}, note = {Online available at: \url{https://doi.org/10.1063/1.5084138} (DOI). Shang, G.; Häntsch, Y.; Furlan, K.; Janßen, R.; Schneider, G.; Petrov, A.; Eich, M.: Highly selective photonic glass filter for saturated blue structural color. APL Photonics. 2019. vol. 4, no. 4, 046101. DOI: 10.1063/1.5084138}} @misc{shang_transparency_induced_2019, author={Shang, G., Furlan, K.P., Zierold, R., Blick, R.H., Janßen, R., Petrov, A., Eich, M.}, title={Transparency induced in opals via nanometer thick conformal coating}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1038/s41598-019-47963-2}, abstract = {Self-assembled periodic structures out of monodisperse spherical particles, so-called opals, are a versatile approach to obtain 3D photonic crystals. We show that a thin conformal coating of only several nanometers can completely alter the reflection properties of such an opal. Specifically, a coating with a refractive index larger than that of the spherical particles can eliminate the first photonic band gap of opals. To explain this non-intuitive effect, where a nm-scaled coating results in a drastic change of optical properties at wavelengths a hundred times bigger, we split the permittivity distribution of the opal into a lattice function convoluted with that of core-shell particles as a motif. In reciprocal space, the Bragg peaks that define the first Brillouin zone can be eliminated if the motif function, which is multiplied, assumes zero at the Bragg peak positions. Therefore, we designed a non-monotonic refractive index distribution from the center of the particle through the shell into the background and adjusted the coating thickness. The theory is supported by simulations and experiments that a nanometer thin TiO2 coating via atomic layer deposition (ALD) on synthetic opals made from polystyrene particles induces nearly full transparency at a wavelength range where the uncoated opal strongly reflects. This effect paves the way for sensing applications such as monitoring the thicknesses growth in ALD in-situ and in real time as well as measuring a refractive index change without spectral interrogation.}, note = {Online available at: \url{https://doi.org/10.1038/s41598-019-47963-2} (DOI). Shang, G.; Furlan, K.; Zierold, R.; Blick, R.; Janßen, R.; Petrov, A.; Eich, M.: Transparency induced in opals via nanometer thick conformal coating. Scientific Reports. 2019. vol. 9, no. 1, 11379. DOI: 10.1038/s41598-019-47963-2}} @misc{graf_surfacetovolume_ratio_2019, author={Graf, M., Jalas, D., Weissmüller, J., Petrov, A.Y., Eich, M.}, title={Surface-to-Volume Ratio Drives Photoelelectron Injection from Nanoscale Gold into Electrolyte}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acscatal.9b00384}, abstract = {Hot charge carriers from plasmonic nanomaterials currently receive increased attention because of their promising potential in important applications such as solar water splitting. While a number of important contributions were made on plasmonic charge carrier generation and their transfer into the metal’s surrounding in the last decades, the local origin of those carriers is still unclear. With our study employing a nanoscaled bicontinuous network of nanoporous gold, we take a comprehensive look at both subtopics in one approach and give unprecedented insights into the physical mechanisms controlling the broadband optical absorption and the generation and injection of hot electrons into an adjacent electrolyte where they enhance electrocatalytic hydrogen evolution. This absorption behavior is very different from the well-known localized surface plasmon resonance effects observed in metallic nanoparticles. For small ligament sizes, the plasmon decay in our network is strongly enhanced via surface collisions of electrons. These surface collisions are responsible for the energy transfer to the carriers and thus the creation of hot electrons from a broad spectrum of photon energies. As we reduce the gold ligament sizes below 30 nm, we demonstrate an occurring transition from absorption that is purely exciting 5d-electrons from deep below the Fermi level to an absorption which significantly excites “free” 6sp-electrons to be emitted. We differentiate these processes via assessing the internal quantum efficiency of the gold network photoelectrode as a function of the feature size providing a size-dependent understanding of the hot electron generation and injection processes in nanoscale plasmonic systems. We demonstrate that the surface effect, compared with the volume effect, becomes dominant and leads to significantly improved efficiencies. The most important fact to recognize is that in the surface photoeffect presented here, absorption and electron transfer are both part of the same quantum mechanical event.}, note = {Online available at: \url{https://doi.org/10.1021/acscatal.9b00384} (DOI). Graf, M.; Jalas, D.; Weissmüller, J.; Petrov, A.; Eich, M.: Surface-to-Volume Ratio Drives Photoelelectron Injection from Nanoscale Gold into Electrolyte. ACS Catalysis. 2019. vol. 9, no. 4, 3366-3374. DOI: 10.1021/acscatal.9b00384}} @misc{bergemann_a_new_2019, author={Bergemann, N., Pistidda, C., Uptmoor, M., Milanese, C., Santoru, A., Emmler, T., Puszkiel, J., Dornheim, M., Klassen, T.}, title={A new mutually destabilized reactive hydride system: LiBH4–Mg2NiH4}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jechem.2019.03.011}, abstract = {In this work, the hydrogen sorption properties of the LiBH4–Mg2NiH4 composite system with the molar ratio 2:2.5 were thoroughly investigated as a function of the applied temperature and hydrogen pressure. To the best of our knowledge, it has been possible to prove experimentally the mutual destabilization between LiBH4 and Mg2NiH4. A detailed account of the kinetic and thermodynamic features of the dehydrogenation process is reported here.}, note = {Online available at: \url{https://doi.org/10.1016/j.jechem.2019.03.011} (DOI). Bergemann, N.; Pistidda, C.; Uptmoor, M.; Milanese, C.; Santoru, A.; Emmler, T.; Puszkiel, J.; Dornheim, M.; Klassen, T.: A new mutually destabilized reactive hydride system: LiBH4–Mg2NiH4. Journal of Energy Chemistry. 2019. vol. 34, 240-254. DOI: 10.1016/j.jechem.2019.03.011}} @misc{thiangviriya_hydrogen_sorption_2019, author={Thiangviriya, S., Sitthiwet, C., Plerdsranoy, P., Capurso, G., Pistidda, C., Utke, O., Dornheim, M., Klassen, T., Utke, R.}, title={Hydrogen sorption kinetics, hydrogen permeability, and thermal properties of compacted 2LiBH4single bondMgH2 doped with activated carbon nanofibers}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2019.04.146}, abstract = {To improve the packing efficiency in tank scale, hydrides have been compacted into pellet form; however, poor hydrogen permeability through the pellets results in sluggish kinetics. In this work, the hydrogen sorption properties of compacted 2LiBH4single bondMgH2 doped with 30 wt % activated carbon nanofibers (ACNF) are investigated. After doping with ACNF, onset dehydrogenation temperature of compacted 2LiBH4single bondMgH2 decreases from 350 to 300 °C and hydrogen released content enhances from 55 to 87% of the theoretical capacity. The sample containing ACNF releases hydrogen following a two-step mechanism with reversible hydrogen storage capacities up to 4.5 wt % H2 and 41.8 gH2/L, whereas the sample without ACNF shows a single-step decomposition mainly from MgH2 with only 1.8 wt % H2 and 15.4 gH2/L. Significant kinetic improvement observed in the doped system is due to the enhancement of both hydrogen permeability and heat transfer through the pellet.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2019.04.146} (DOI). Thiangviriya, S.; Sitthiwet, C.; Plerdsranoy, P.; Capurso, G.; Pistidda, C.; Utke, O.; Dornheim, M.; Klassen, T.; Utke, R.: Hydrogen sorption kinetics, hydrogen permeability, and thermal properties of compacted 2LiBH4single bondMgH2 doped with activated carbon nanofibers. International Journal of Hydrogen Energy. 2019. vol. 44, no. 29, 15218-15227. DOI: 10.1016/j.ijhydene.2019.04.146}} @misc{milanese_complex_hydrides_2019, author={Milanese, C., Jensen, T., Hauback, B., Pistidda, C., Dornheim, M., Yang, H., Lombardo, L., Züttel, A., Filinchuk, Y., de Jongh, P., Buckley, C., Dematteis, E., Baricco, M.}, title={Complex hydrides for energy storage}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2018.11.208}, abstract = {In the past decades, complex hydrides and complex hydrides-based materials have been thoroughly investigated as materials for energy storage, owing to their very high gravimetric and volumetric hydrogen capacities and interesting cation and hydrogen diffusion properties. Concerning hydrogen storage, the main limitations of this class of materials are the high working temperatures and pressures, the low hydrogen absorption and desorption rates and the poor cyclability. In the past years, research in this field has been focused on understanding the hydrogen release and uptake mechanism of the pristine and catalyzed materials and on the characterization of the thermodynamic aspects, in order to rationally choose the composition and the stoichiometry of the systems in terms of hydrogen active phases and catalysts/destabilizing agents. Moreover, new materials have been discovered and characterized in an attempt to find systems with properties suitable for practical on-board and stationary applications. A significant part of this rich and productive activity has been performed by the research groups led by the Experts of the International Energy Agreement Task 32, often in collaborative research projects. The most recent findings of these joint activities and other noteworthy recent results in the field are reported in this paper.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2018.11.208} (DOI). Milanese, C.; Jensen, T.; Hauback, B.; Pistidda, C.; Dornheim, M.; Yang, H.; Lombardo, L.; Züttel, A.; Filinchuk, Y.; de Jongh, P.; Buckley, C.; Dematteis, E.; Baricco, M.: Complex hydrides for energy storage. International Journal of Hydrogen Energy. 2019. vol. 44, no. 15, 7860-7874. DOI: 10.1016/j.ijhydene.2018.11.208}} @misc{valentoni_a_mechanochemical_2019, author={Valentoni, A., Barra, P., Senes, N., Mulas, G., Pistidda, C., Bednarcik, J., Torre, F., Garroni, S., Enzo, S.}, title={A mechanochemical route for the synthesis of VNbO5 and its structural re-investigation using structure solution from powder diffraction data}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c9dt01236b}, abstract = {A new and solvent-free synthesis route has been adopted and optimized to prepare crystalline VNbO5 from the mechanochemical reaction between Nb2O5 and V2O5 as starting reagents. The substantially amorphous mixture of equimolar pentoxide V and Nb metals observed after extended mechanical treatment transforms into a crystalline powder following calcination under mild conditions at 710 K. The structure solution of the X-ray diffraction pattern using a global optimization approach, combined with Rietveld refinement, points to a space group P212121 (no. 19) different from Pnma (no. 62) previously proposed in the literature assuming it to be isostructural to VTaO5. The new space group helps to describe weak peaks that remained previously unaccounted for and allows more reliable determination of atomic fractional coordinates and interatomic distance distribution. The as-prepared VNbO5 has been tested as a dopant (5 wt%) for the purpose of solid state hydrogen storage, decreasing significantly the release of hydrogen of MgH2/Mg (620 K) and further enhancing the hydrogen sorption kinetic properties.}, note = {Online available at: \url{https://doi.org/10.1039/c9dt01236b} (DOI). Valentoni, A.; Barra, P.; Senes, N.; Mulas, G.; Pistidda, C.; Bednarcik, J.; Torre, F.; Garroni, S.; Enzo, S.: A mechanochemical route for the synthesis of VNbO5 and its structural re-investigation using structure solution from powder diffraction data. Dalton Transactions. 2019. vol. 48, no. 29, 10986-10995. DOI: 10.1039/c9dt01236b}} @misc{grasso_co2_reutilization_2019, author={Grasso, M., Puszkiel, J., Fernandez Albanesi, L., Dornheim, M., Pistidda, C., Gennari, F.}, title={CO2 reutilization for methane production via a catalytic process promoted by hydrides}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c9cp03826d}, abstract = {CO2 emissions have been continuously increasing during the last half of the century with a relevant impact on the planet and are the main contributor to the greenhouse effect and global warming. The development of new technologies to mitigate these emissions poses a challenge. Herein, the recycling of CO2 to produce CH4 selectively by using Mg2FeH6 and Mg2NiH4 complex hydrides as dual conversion promoters and hydrogen sources has been demonstrated. Magnesium-based metal hydrides containing Fe and Ni catalyzed the hydrogenation of CO2 and their total conversion was obtained at 400 °C after 5 h and 10 h, respectively. The complete hydrogenation of CO2 depended on the complex hydride, H2 : CO2 mol ratio, and experimental conditions: temperature and time. For both hydrides, the activation of CO2 on the metal surface and its subsequent capture resulted in the formation of MgO. Investigations on the Mg2FeH6–CO2 system indicated that the main process occurs via the reversed water–gas shift reaction (WGSR), followed by the methanation of CO in the presence of steam. In contrast, the reduction of CO2 by the Mg-based hydride in the Mg2NiH4–CO2 system has a strong contribution to the global process. Complex metal hydrides are promising dual promoter-hydrogen sources for CO2 recycling and conversion into valuable fuels such as CH4.}, note = {Online available at: \url{https://doi.org/10.1039/c9cp03826d} (DOI). Grasso, M.; Puszkiel, J.; Fernandez Albanesi, L.; Dornheim, M.; Pistidda, C.; Gennari, F.: CO2 reutilization for methane production via a catalytic process promoted by hydrides. Physical Chemistry Chemical Physics. 2019. vol. 21, no. 36, 19825-19834. DOI: 10.1039/c9cp03826d}} @misc{mortalo_structural_evolution_2019, author={Mortalo, C., Santoru, A., Pistidda, C., Rebollo, E., Boaro, M., Leonelli, C., Fabrizio, M.}, title={Structural evolution of BaCe0.65Zr0.20Y0.15O3-δ-Ce0.85Gd0.15O2-δ composite MPEC membrane by in-situ synchrotron XRD analyses}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.mtener.2019.06.004}, abstract = {Nowadays, dense ceramic membranes based on mixed ionic and electronic conductors are considered very promising materials for H2 separation at T > 600 °C. Among these, BaCe0.65Zr0.2Y0.15O3-δ-Ce0.85Gd0.15O2-δ (BCZ20Y15-GDC15) composite combine an acceptable H2 flux and good chemical stability under CO2- and H2S-containing atmospheres. However, a clear understanding of its crystal structure, phase stability and mechanical stability under real working conditions could not yet be obtained. In this work, its structural evolution was investigated from room temperature to 800 °C by in-situ synchrotron XRD analyses under dry and wet H2. No chemical interaction between the BCZ20Y15 and GDC15 phases occurred in the composite, thus demontrating its excellent chemical stability under operating conditions. However, some phase transitions were observed for the BCZ20Y15 phase, under both dry and wet H2: i.e., it showed an orthorhombic Imma structure from room temperature to 100 °C, trigonal R-3c up to 700 °C and cubic Pm-3m up to 800 °C. On the other hand, the GDC15 phase did not display any phase transition, remaining in a cubic Fm-3m structure under all tested conditions. Moreover, a synergistic effect of the BCZ20Y15 and GDC15 phases in the volume expansion of the composite was revealed: indeed, BCZ20Y15 and GDC15 lattice expansion rates tend to approach each other in the composite under reducing conditions. This synergistic effect is very important for the mechanical performances of BCZ20Y15-GDC15 composite. The similar expansion rate observed for BCZ20Y15 and GDC15 may reduce the strain and prevent failure of this ceramic membrane under operating conditions.}, note = {Online available at: \url{https://doi.org/10.1016/j.mtener.2019.06.004} (DOI). Mortalo, C.; Santoru, A.; Pistidda, C.; Rebollo, E.; Boaro, M.; Leonelli, C.; Fabrizio, M.: Structural evolution of BaCe0.65Zr0.20Y0.15O3-δ-Ce0.85Gd0.15O2-δ composite MPEC membrane by in-situ synchrotron XRD analyses. Materials Today Energy. 2019. vol. 13, 331-341. DOI: 10.1016/j.mtener.2019.06.004}} @misc{dematteis_exploring_ternary_2019, author={Dematteis, E., Pistidda, C., Dornheim, M., Baricco, M.}, title={Exploring Ternary and Quaternary Mixtures in the LiBH4-NaBH4-KBH4-Mg(BH4)2-Ca(BH4)2 System}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1002/cphc.201801130}, abstract = {Binary combinations of borohydrides have been extensivly investigated evidencing the formation of eutectics, bimetallic compounds or solid solutions. In this paper, the investigation has been extended to ternary and quaternary systems in the LiBH4-NaBH4-KBH4-Mg(BH4)2-Ca(BH4)2 system. Possible interactions among borohydrides in equimolar composition has been explored by mechanochemical treatment. The obtained phases were analysed by X-ray diffraction and the thermal behaviour of the mixtures were analysed by HP-DSC and DTA, defining temperature of transitions and decomposition reactions. The release of hydrogen was detected by MS, showing the role of the presence of solid solutions and multi-cation compounds on the hydrogen desorption reactions. The presence of LiBH4 generally promotes the release of H2 at about 200 °C, while KCa(BH4)3 promotes the release in a single-step reaction at higher temperatures.}, note = {Online available at: \url{https://doi.org/10.1002/cphc.201801130} (DOI). Dematteis, E.; Pistidda, C.; Dornheim, M.; Baricco, M.: Exploring Ternary and Quaternary Mixtures in the LiBH4-NaBH4-KBH4-Mg(BH4)2-Ca(BH4)2 System. ChemPhysChem. 2019. vol. 20, no. 10, 1348-1359. DOI: 10.1002/cphc.201801130}} @misc{sinn_the_sase1_2019, author={Sinn, H., Dommach, M., Dickert, B., Di Felice, M., Dong, X., Eidam, J., Finze, D., Freijo-Martin, I., Gerasimova, N., Kohlstrunk, N., La Civita, D., Meyn, F., Music, V., Neumann, M., Petrich, M., Rio, B., Samoylova, L., Schmidtchen, S., Störmer, M., Trapp, A., Vannoni, M., Villanueva, R., Yang, F.}, title={The SASE1 X-ray beam transport system}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S1600577519003461}, abstract = {SASE1 is the first beamline of the European XFEL that became operational in 2017. It consists of the SASE1 undulator system, the beam transport system, and the two scientific experiment stations: Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography (SPB/SFX), and Femtosecond X-ray Experiments (FXE). The beam transport system comprises mirrors to offset and guide the beam to the instruments and a set of X-ray optical components to align, manipulate and diagnose the beam. The SASE1 beam transport system is described here in its initial configuration, and results and experiences from the first year of user operation are reported.}, note = {Online available at: \url{https://doi.org/10.1107/S1600577519003461} (DOI). Sinn, H.; Dommach, M.; Dickert, B.; Di Felice, M.; Dong, X.; Eidam, J.; Finze, D.; Freijo-Martin, I.; Gerasimova, N.; Kohlstrunk, N.; La Civita, D.; Meyn, F.; Music, V.; Neumann, M.; Petrich, M.; Rio, B.; Samoylova, L.; Schmidtchen, S.; Störmer, M.; Trapp, A.; Vannoni, M.; Villanueva, R.; Yang, F.: The SASE1 X-ray beam transport system. Journal of Synchrotron Radiation. 2019. vol. 26, 692-699. DOI: 10.1107/S1600577519003461}} @misc{aquila_erratum_fluence_2019, author={Aquila, A., Sobierajski, R., Ozkan, C., Hájková, V., Burian, T., Chalupský, J., Juha, L., Störmer, M., Bajt, S., Klepka, M.T., Dłuzewski, P., Morawiec, K., Ohashi, H., Koyama, T., Tono, K., Inubushi, Y., Yabashi, M., Sinn, H., Tschentscher, T., Mancuso, A.P., Gaudin, J.}, title={Erratum: “Fluence thresholds for grazing incidence hard x-ray mirrors” [Appl. Phys. Lett. 106, 241905 (2015)]}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1063/1.5114937}, note = {Online available at: \url{https://doi.org/10.1063/1.5114937} (DOI). Aquila, A.; Sobierajski, R.; Ozkan, C.; Hájková, V.; Burian, T.; Chalupský, J.; Juha, L.; Störmer, M.; Bajt, S.; Klepka, M.; Dłuzewski, P.; Morawiec, K.; Ohashi, H.; Koyama, T.; Tono, K.; Inubushi, Y.; Yabashi, M.; Sinn, H.; Tschentscher, T.; Mancuso, A.; Gaudin, J.: Erratum: “Fluence thresholds for grazing incidence hard x-ray mirrors” [Appl. Phys. Lett. 106, 241905 (2015)]. Applied Physics Letters. 2019. vol. 115, 059901. DOI: 10.1063/1.5114937}} @misc{chirumamilla_metamaterial_emitter_2019, author={Chirumamilla, M., Krishnamurthy, G., Knopp, K., Krekeler, T., Graf, M., Jalas, D., Ritter, M., Störmer, M., Petrov, A., Eich, M.}, title={Metamaterial emitter for thermophotovoltaics stable up to 1400 °C}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1038/s41598-019-43640-6}, abstract = {High temperature stable selective emitters can significantly increase efficiency and radiative power in thermophotovoltaic (TPV) systems. However, optical properties of structured emitters reported so far degrade at temperatures approaching 1200 °C due to various degradation mechanisms. We have realized a 1D structured emitter based on a sputtered W-HfO2 layered metamaterial and demonstrated desired band edge spectral properties at 1400 °C. To the best of our knowledge the temperature of 1400 °C is the highest reported for a structured emitter, so far. The spatial confinement and absence of edges stabilizes the W-HfO2 multilayer system to temperatures unprecedented for other nanoscaled W-structures. Only when this confinement is broken W starts to show the well-known self-diffusion behavior transforming to spherical shaped W-islands. We further show that the oxidation of W by atmospheric oxygen could be prevented by reducing the vacuum pressure below 10−5 mbar. When oxidation is mitigated we observe that the 20 nm spatially confined W films survive temperatures up to 1400 °C. The demonstrated thermal stability is limited by grain growth in HfO2, which leads to a rupture of the W-layers, thus, to a degradation of the multilayer system at 1450 °C.}, note = {Online available at: \url{https://doi.org/10.1038/s41598-019-43640-6} (DOI). Chirumamilla, M.; Krishnamurthy, G.; Knopp, K.; Krekeler, T.; Graf, M.; Jalas, D.; Ritter, M.; Störmer, M.; Petrov, A.; Eich, M.: Metamaterial emitter for thermophotovoltaics stable up to 1400 °C. Scientific Reports. 2019. vol. 9, 7241. DOI: 10.1038/s41598-019-43640-6}} @misc{sofianos_hydrogen_storage_2019, author={Sofianos, M.V., Chaudhary, A.-L., Paskevicius, M., Sheppard, D.A., Humphries, T.D., Dornheim, M., Buckley, C.E.}, title={Hydrogen storage properties of eutectic metal borohydrides melt-infiltrated into porous Al scaffolds}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2018.10.086}, abstract = {Porous Al scaffolds were synthesised and melt-infiltrated with various eutectic metal borohydride mixtures (0.725LiBH4-0.275KBH4, 0.68NaBH4-0.32KBH4, 0.4NaBH4-0.6 Mg(BH4)2) to simultaneously act as both a confining framework and a reactive destabilising agent for H2 release. The scaffolds were synthesised by sintering a pellet of NaAlH4/2 mol%TiCl3 at 450 °C under dynamic vacuum. During the sintering process the sodium alanate (NaAlH4) decomposed to Al metal. The vacuum applied at elevated temperature promoted the Na metal to vaporise and be extruded from the pellet. The pores of the resulting Al scaffold were created during removal of the H2 and the Na from the body of the NaAlH4/2 mol%TiCl3 pellet. According to the morphological observations carried out by a Scanning Electron Microscope (SEM), melt-infiltrated eutectic mixtures of metal borohydrides were highly dispersed into the porous scaffolds. Temperature Programmed Desorption (TPD) experiments, revealed that the melt-infiltrated samples exhibited faster H2 desorption kinetics in comparison to bulk samples, with onset temperatures (Tdes) lower than the bulk by 150–250 °C. The as-synthesised porous Al scaffolds acted as a reactive containment vessel for these eutectic mixtures that simultaneously nanoconfined and destabilised the mixtures.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2018.10.086} (DOI). Sofianos, M.; Chaudhary, A.; Paskevicius, M.; Sheppard, D.; Humphries, T.; Dornheim, M.; Buckley, C.: Hydrogen storage properties of eutectic metal borohydrides melt-infiltrated into porous Al scaffolds. Journal of Alloys and Compounds. 2019. vol. 775, 474-480. DOI: 10.1016/j.jallcom.2018.10.086}} @misc{jepsen_fundamental_material_2018, author={Jepsen, J., Milanese, C., Puszkiel, J., Girella, A., Schiavo, B., Lozano, G.A., Capurso, G., Bellosta von Colbe, J.M., Marini, A., Kabelac, S., Dornheim, M., Klassen, T.}, title={Fundamental Material Properties of the 2LiBH4-MgH2 Reactive Hydride Composite for Hydrogen Storage: (II) Kinetic Properties}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.3390/en11051170}, abstract = {Reaction kinetic behaviour and cycling stability of the 2LiBH4–MgH2 reactive hydride composite (Li-RHC) are experimentally determined and analysed as a basis for the design and development of hydrogen storage tanks. In addition to the determination and discussion about the properties; different measurement methods are applied and compared. The activation energies for both hydrogenation and dehydrogenation are determined by the Kissinger method and via the fitting of solid-state reaction kinetic models to isothermal volumetric measurements. Furthermore, the hydrogen absorption–desorption cycling stability is assessed by titration measurements. Finally, the kinetic behaviour and the reversible hydrogen storage capacity of the Li-RHC are discussed.}, note = {Online available at: \url{https://doi.org/10.3390/en11051170} (DOI). Jepsen, J.; Milanese, C.; Puszkiel, J.; Girella, A.; Schiavo, B.; Lozano, G.; Capurso, G.; Bellosta von Colbe, J.; Marini, A.; Kabelac, S.; Dornheim, M.; Klassen, T.: Fundamental Material Properties of the 2LiBH4-MgH2 Reactive Hydride Composite for Hydrogen Storage: (II) Kinetic Properties. Energies. 2018. vol. 11, no. 5, 1170. DOI: 10.3390/en11051170}} @misc{santoru_insights_into_2018, author={Santoru, A., Pistidda, C., Brighi, M., Chierotti, M.R., Heere, M., Karimi, F., Cao, H., Capurso, G., Chaudhary, A.-L., Gizer, G., Garroni, S., Soerby, M., Hauback, B.C., Cerny, R., Klassen, T., Dornheim, M.}, title={Insights into the Rb–Mg–N–H System: an Ordered Mixed Amide/Imide Phase and a Disordered Amide/Hydride Solid Solution}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.inorgchem.7b03232}, abstract = {The crystal structure of a mixed amide-imide phase, RbMgND2ND, has been solved in the orthorhombic space group Pnma (a = 9.55256(31), b = 3.70772(11) and c = 10.08308(32) Å). A new metal amide-hydride solid solution, Rb(NH2)xH(1–x), has been isolated and characterized in the entire compositional range. The profound analogies, as well as the subtle differences, with the crystal chemistry of KMgND2ND and K(NH2)xH1–x are thoroughly discussed. This approach suggests that the comparable performances obtained using K- and Rb-based additives for the Mg(NH2)2-2LiH and 2LiNH2–MgH2 hydrogen storage systems are likely to depend on the structural similarities of possible reaction products and intermediates.}, note = {Online available at: \url{https://doi.org/10.1021/acs.inorgchem.7b03232} (DOI). Santoru, A.; Pistidda, C.; Brighi, M.; Chierotti, M.; Heere, M.; Karimi, F.; Cao, H.; Capurso, G.; Chaudhary, A.; Gizer, G.; Garroni, S.; Soerby, M.; Hauback, B.; Cerny, R.; Klassen, T.; Dornheim, M.: Insights into the Rb–Mg–N–H System: an Ordered Mixed Amide/Imide Phase and a Disordered Amide/Hydride Solid Solution. Inorganic Chemistry. 2018. vol. 57, no. 6, 3197-3205. DOI: 10.1021/acs.inorgchem.7b03232}} @misc{dahms_a_simple_2018, author={Dahms, M., Hoeche, D., Ahmad Agha, N., Feyerabend, F., Willumeit-Roemer, R.}, title={A simple model for long-time degradation of magnesium under physiological conditions}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1002/maco.201709461}, abstract = {The present work applies the law of mass conservation toward an analytical model describing the long-term degradation of Mg-0.3Ca implant material in defined physiological electrolyte environments. The model takes into account surface conversion and degradation product deposition related changes of degradation rates by introducing an effective layer thickness. The analytical nature of the approach does not consider detailed chemical and electrochemical process. Thus, it simply declares an effective damping term. In this way it can be applied easily for the prediction of materials failure in the named environments. Restrictions of the approach will be discussed as well since validity relates to a number of aspects.}, note = {Online available at: \url{https://doi.org/10.1002/maco.201709461} (DOI). Dahms, M.; Hoeche, D.; Ahmad Agha, N.; Feyerabend, F.; Willumeit-Roemer, R.: A simple model for long-time degradation of magnesium under physiological conditions. Materials and Corrosion. 2018. vol. 69, no. 2, 191-196. DOI: 10.1002/maco.201709461}} @misc{cao_airstable_metal_2018, author={Cao, H., Georgopanos, P., Capurso, G., Pistidda, C., Weigelt, F., Chaudhary, A.-L., Filiz, V., Tseng, J.-C., Wharmby, M.T., Dornheim, M., Abetz, V., Klassen, T.}, title={Air-stable metal hydride-polymer composites of Mg(NH2)2–LiH and TPX™}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.mtener.2018.08.008}, abstract = {Light metal hydrides are prone to react with oxygen and/or water to produce oxides and/or hydroxides leading to reduction of hydrogen capacities, and deterioration of the hydrogen storage properties. It is therefore critical to address these issues when the materials are to be exposed to air or moisture. In this work, the combination of light metal hydrides, Mg(NH2)2–nLiH with polymethylpentene (TPX™), an air/moisture protective barrier is presented. It was found that the fabricated composites exhibit significant improvement of the metal hydrides stability in air. No oxidation reactions in air can be proven even after air exposure for 90 min. Extending the air-exposure time to 12 h, the reversible hydrogen capacities of these composites are much higher and more stable than they are in the case of the pure metal hydrides. In comparison to the pure metal hydrides, the composites retain the same hydrogen loading capacities and kinetic properties, with respect to the metal hydrides contents. Further, in situ synchrotron radiation powder X-ray radiation diffraction (SR-PXRD) experiments reveal that the thermal decomposition reaction pathways of the 90 min air-exposed composites are the same under air or H2 atmosphere. Moreover, morphology analysis confirms that the metal hydrides remain stable in the polymeric matrix and the three-dimensional integrity is retained, even after performing tens of de/re-hydrogenation cycles. The present study shows a promising way to fabricate air-stable metal hydride-polymer composite hydrogen storage materials that can be handled in ambient conditions.}, note = {Online available at: \url{https://doi.org/10.1016/j.mtener.2018.08.008} (DOI). Cao, H.; Georgopanos, P.; Capurso, G.; Pistidda, C.; Weigelt, F.; Chaudhary, A.; Filiz, V.; Tseng, J.; Wharmby, M.; Dornheim, M.; Abetz, V.; Klassen, T.: Air-stable metal hydride-polymer composites of Mg(NH2)2–LiH and TPX™. Materials Today : Energy. 2018. vol. 10, 98-107. DOI: 10.1016/j.mtener.2018.08.008}} @misc{jepsen_fundamental_material_2018, author={Jepsen, J., Milanese, C., Puszkiel, J., Girella, A., Schiavo, B., Lozano, G.A., Capurso, G., Bellosta von Colbe, J.M., Marini, A., Kabelac, S., Dornheim, M., Klassen, T.}, title={Fundamental Material Properties of the 2LiBH4-MgH2 Reactive Hydride Composite for Hydrogen Storage: (I) Thermodynamic and Heat Transfer Properties}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.3390/en11051081}, abstract = {Thermodynamic and heat transfer properties of the 2LiBH4-MgH2 composite (Li-RHC) system are experimentally determined and studied as a basis for the design and development of hydrogen storage tanks. Besides the determination and discussion of the properties, different measurement methods are applied and compared to each other. Regarding thermodynamics, reaction enthalpy and entropy are determined by pressure-concentration-isotherms and coupled manometric-calorimetric measurements. For thermal diffusivity calculation, the specific heat capacity is measured by high-pressure differential scanning calorimetry and the effective thermal conductivity is determined by the transient plane source technique and in situ thermocell. Based on the results obtained from the thermodynamics and the assessment of the heat transfer properties, the reaction mechanism of the Li-RHC and the issues related to the scale-up for larger hydrogen storage systems are discussed in detail.}, note = {Online available at: \url{https://doi.org/10.3390/en11051081} (DOI). Jepsen, J.; Milanese, C.; Puszkiel, J.; Girella, A.; Schiavo, B.; Lozano, G.; Capurso, G.; Bellosta von Colbe, J.; Marini, A.; Kabelac, S.; Dornheim, M.; Klassen, T.: Fundamental Material Properties of the 2LiBH4-MgH2 Reactive Hydride Composite for Hydrogen Storage: (I) Thermodynamic and Heat Transfer Properties. Energies. 2018. vol. 11, no. 5, 1081. DOI: 10.3390/en11051081}} @misc{wolff_in_vitro_2018, author={Wolff, M., Luczak, M., Schaper, J.G., Wiese, B., Dahms, M., Ebel, T., Willumeit-Roemer, R., Klassen, T.}, title={In vitro biodegradation testing of Mg-alloy EZK400 and manufacturing of implant prototypes using PM (powder metallurgy) methods}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.bioactmat.2018.03.002}, abstract = {The study is focussing towards Metal Injection Moulding (MIM) of Mg-alloys for biomedical implant applications. Especially the influence of the sintering processing necessary for the consolidation of the finished part is in focus of this study. In doing so, the chosen high strength EZK400 Mg-alloy powder material was sintered using different sintering support bottom plate materials to evaluate the possibility of iron impurity pick up during sintering. It can be shown that iron pick up took place from the steel bottom plate into the specimen. Despite the fact that a separating boron nitrite (BN) barrier layer was used and the Mg-Fe phase diagram is not predicting any significant solubility to each other. As a result of this study a new bottom plate material not harming the sintering and the biodegradation performance of the as sintered material, namely a carbon plate material, was found.}, note = {Online available at: \url{https://doi.org/10.1016/j.bioactmat.2018.03.002} (DOI). Wolff, M.; Luczak, M.; Schaper, J.; Wiese, B.; Dahms, M.; Ebel, T.; Willumeit-Roemer, R.; Klassen, T.: In vitro biodegradation testing of Mg-alloy EZK400 and manufacturing of implant prototypes using PM (powder metallurgy) methods. Bioactive Materials. 2018. vol. 3, no. 3, 213-217. DOI: 10.1016/j.bioactmat.2018.03.002}} @misc{mgbemere_synthesis_of_2018, author={Mgbemere, H.E., Lawal, G.I., Ekpe, I.C., Chaudhary, A.-L.}, title={Synthesis of zeolite-A using kaolin samples from Darazo, Bauchi state and Ajebo, Ogun state in Nigeria}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.4314/njt.v37i1.12}, abstract = {Kaolin samples from Ajebo and Darazo in Nigeria were characterized and used to produce zeolite - A crystals. The thermal analysis indicates that both samples under gode-hydroxylation from 450oC to about 700oC and are converted to metakaolin with a weight lo ss of about 11.39 and 10.43% for the Ajebo and Darazo samples respectively. Characteristic OH, Al-OH, Si-OH and Si-O-Albands were confirmed in both samples with Infra-red spectroscopy studies. The X - ray diffraction patterns clearly show the presence of the characteristic peaks (12.35 and 24.88o ) of kaolinite with little quartz impurities. X - ray diffraction measurements (2Ɵ peaks at 7 – 18o and 21 – 35o ) and scanning electron micro graphs clearly show that zeolite - A crystals are produced. The microstructures of kaolin, metakaolin and zeolite - A crystals reveal the presence of platy crystals, amorphous spherical aggregates and cubic - shaped crystals with some amorphous gel respectively . The results show that both Ajebo and Darazo kaolin are suitable for zeolite - A synthesis.}, note = {Online available at: \url{https://doi.org/10.4314/njt.v37i1.12} (DOI). Mgbemere, H.; Lawal, G.; Ekpe, I.; Chaudhary, A.: Synthesis of zeolite-A using kaolin samples from Darazo, Bauchi state and Ajebo, Ogun state in Nigeria. Nigerian Journal of Technology. 2018. vol. 37, no. 1, 87-95. DOI: 10.4314/njt.v37i1.12}} @misc{capurso_metal_hydridebased_2018, author={Capurso, G., Schiavo, B., Jepsen, J., Lozano, G.A., Metz, O., Klassen, T., Dornheim, M.}, title={Metal Hydride‐Based Hydrogen Storage Tank Coupled with an Urban Concept Fuel Cell Vehicle: Off Board Tests}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1002/adsu.201800004}, abstract = {In this work, the tests of a hydrogen storage system intended for vehicular applications, using a metal hydride as storage material, are reported. The system is designed to deliver gas to a fuel cell prototype vehicle. The room temperature hydride is an interstitial alloy, which is selected for its capacity to absorb and desorb hydrogen over an appropriate range of temperature and pressure. The static tests aim to assess whether the requirements for hydrogen release are reliably met by the tank setup. Hypothetical on‐road tests have been designed and applied. Dynamic tests allow moving from energy to power density. Solutions are adopted to face the issues of thermal management at higher‐demanding performances. Several cycles have been performed to find the ideal settings to preserve high average and peak gas flow in a realistic situation. The use of a metal hydride, to replace pressurized gas, results in improved performances, including an extended range at lower loading pressures. Decreasing the pressure in the storage system enables the advantageous possibility to reload the tank several times with commercially available cylinders. Possible future enhancements in the reduction of the total weight of the system are also considered.}, note = {Online available at: \url{https://doi.org/10.1002/adsu.201800004} (DOI). Capurso, G.; Schiavo, B.; Jepsen, J.; Lozano, G.; Metz, O.; Klassen, T.; Dornheim, M.: Metal Hydride‐Based Hydrogen Storage Tank Coupled with an Urban Concept Fuel Cell Vehicle: Off Board Tests. Advanced Sustainable Systems. 2018. vol. 2, no. 6, 1800004. DOI: 10.1002/adsu.201800004}} @misc{puszkiel_new_insight_2018, author={Puszkiel, J., Castro Riglos, M.V., Ramallo-Lopez, J.M., Mizrahi, M., Gemming, T., Pistidda, C., Larochette, P.A., Bellosta von Colbe, J., Klassen, T., Dornheim, M., Gennari, F.}, title={New Insight on the Hydrogen Absorption Evolution of the Mg–Fe–H System under Equilibrium Conditions}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.3390/met8110967}, abstract = {Mg2FeH6 is regarded as potential hydrogen and thermochemical storage medium due to its high volumetric hydrogen (150 kg/m3) and energy (0.49 kWh/L) densities. In this work, the mechanism of formation of Mg2FeH6 under equilibrium conditions is thoroughly investigated applying volumetric measurements, X-ray diffraction (XRD), X-ray absorption near edge structure (XANES), and the combination of scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy (EDS) and high-resolution transmission electron microscopy (HR-TEM). Starting from a 2Mg:Fe stoichiometric powder ratio, thorough characterizations of samples taken at different states upon hydrogenation under equilibrium conditions confirm that the formation mechanism of Mg2FeH6 occurs from elemental Mg and Fe by columnar nucleation of the complex hydride at boundaries of the Fe seeds. The formation of MgH2 is enhanced by the presence of Fe. However, MgH2 does not take part as intermediate for the formation of Mg2FeH6 and acts as solid-solid diffusion barrier which hinders the complete formation of Mg2FeH6. This work provides novel insight about the formation mechanism of Mg2FeH6.}, note = {Online available at: \url{https://doi.org/10.3390/met8110967} (DOI). Puszkiel, J.; Castro Riglos, M.; Ramallo-Lopez, J.; Mizrahi, M.; Gemming, T.; Pistidda, C.; Larochette, P.; Bellosta von Colbe, J.; Klassen, T.; Dornheim, M.; Gennari, F.: New Insight on the Hydrogen Absorption Evolution of the Mg–Fe–H System under Equilibrium Conditions. Metals. 2018. vol. 8, no. 11, 967. DOI: 10.3390/met8110967}} @misc{dematteis_reactive_hydride_2018, author={Dematteis, E.M., Vaunois, S., Pistidda, C., Dornheim, M., Baricco, M.}, title={Reactive Hydride Composite of Mg2NiH4 with Borohydrides Eutectic Mixtures}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.3390/cryst8020090}, abstract = {The development of materials showing hydrogen sorption reactions close to room temperature and ambient pressure will promote the use of hydrogen as energy carrier for mobile and stationary large-scale applications. In the present study, in order to reduce the thermodynamic stability of MgH2, Ni has been added to form Mg2NiH4, which has been mixed with various borohydrides to further tune hydrogen release reactions. De-hydrogenation/re-hydrogenation properties of Mg2NiH4-LiBH4-M(BH4)x (M = Na, K, Mg, Ca) systems have been investigated. Mixtures of borohydrides have been selected to form eutectics, which provide a liquid phase at low temperatures, from 110 °C up to 216 °C. The presence of a liquid borohydride phase decreases the temperature of hydrogen release of Mg2NiH4 but only slight differences have been detected by changing the borohydrides in the eutectic mixture.}, note = {Online available at: \url{https://doi.org/10.3390/cryst8020090} (DOI). Dematteis, E.; Vaunois, S.; Pistidda, C.; Dornheim, M.; Baricco, M.: Reactive Hydride Composite of Mg2NiH4 with Borohydrides Eutectic Mixtures. Crystals. 2018. vol. 8, no. 2, 90. DOI: 10.3390/cryst8020090}} @misc{hardian_waste_mgal_2018, author={Hardian, R., Pistidda, C., Chaudhary, A.-L., Capurso, G., Gizer, G., Cao, H., Milanese, C., Girella, A., Santoru, A., Yigit, D., Dieringa, H., Kainer, K.U., Klassen, T., Dornheim, M.}, title={Waste Mg-Al based alloys for hydrogen storage}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2017.12.014}, abstract = {Magnesium has been studied as a potential hydrogen storage material for several decades because of its relatively high hydrogen storage capacity, fast sorption kinetics (when doped with transition metal based additives), and abundance. This research aims to study the possibility to use waste magnesium alloys to produce good quality MgH2. The production costs of hydrogen storage materials is still one of the major barriers disabling scale up for mobile or stationary application. The recycling of magnesium-based waste to produce magnesium hydride will significantly contribute to the cost reduction of this material. This study focuses on the effect of different parameters such as the addition of graphite and/or Nb2O5 as well as the effect of milling time on the material hydrogenation/de-hydrogenation performances. In addition, morphology and microstructural features are also evaluated for all the investigated materials.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2017.12.014} (DOI). Hardian, R.; Pistidda, C.; Chaudhary, A.; Capurso, G.; Gizer, G.; Cao, H.; Milanese, C.; Girella, A.; Santoru, A.; Yigit, D.; Dieringa, H.; Kainer, K.; Klassen, T.; Dornheim, M.: Waste Mg-Al based alloys for hydrogen storage. International Journal of Hydrogen Energy. 2018. vol. 43, no. 34, 16738-16748. DOI: 10.1016/j.ijhydene.2017.12.014}} @misc{le_design_of_2018, author={Le, T., Pistidda, C., Puszkiel, J., Castro Riglos, M., Karimi, F., Skibsted, J., Payandeh GharibDoust, S., Richter, B., Emmler, T., Milanese, C., Santoru, A., Hoell, A., Krumrey, M., Gericke, E., Akiba, E., Jensen, T., Klassen, T., Dornheim, M.}, title={Design of a Nanometric AlTi Additive for MgB2-Based Reactive Hydride Composites with Superior Kinetic Properties}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.jpcc.8b01850}, abstract = {Solid-state hydride compounds are a promising option for efficient and safe hydrogen-storage systems. Lithium reactive hydride composite system 2LiBH4 + MgH2/2LiH + MgB2 (Li-RHC) has been widely investigated owing to its high theoretical hydrogen-storage capacity and low calculated reaction enthalpy (11.5 wt % H2 and 45.9 kJ/mol H2). In this paper, a thorough investigation into the effect of the formation of nano-TiAl alloys on the hydrogen-storage properties of Li-RHC is presented. The additive 3TiCl3·AlCl3 is used as the nanoparticle precursor. For the investigated temperatures and hydrogen pressures, the addition of ∼5 wt % 3TiCl3·AlCl3 leads to hydrogenation/dehydrogenation times of only 30 min and a reversible hydrogen-storage capacity of 9.5 wt %. The material containing 3TiCl3·AlCl3 possesses superior hydrogen-storage properties in terms of rates and a stable hydrogen capacity during several hydrogenation/dehydrogenation cycles. These enhancements are attributed to an in situ nanostructure and a hexagonal AlTi3 phase observed by high-resolution transmission electron microscopy. This phase acts in a 2-fold manner, first promoting the nucleation of MgB2 upon dehydrogenation and second suppressing the formation of Li2B12H12 upon hydrogenation/dehydrogenation cycling.}, note = {Online available at: \url{https://doi.org/10.1021/acs.jpcc.8b01850} (DOI). Le, T.; Pistidda, C.; Puszkiel, J.; Castro Riglos, M.; Karimi, F.; Skibsted, J.; Payandeh GharibDoust, S.; Richter, B.; Emmler, T.; Milanese, C.; Santoru, A.; Hoell, A.; Krumrey, M.; Gericke, E.; Akiba, E.; Jensen, T.; Klassen, T.; Dornheim, M.: Design of a Nanometric AlTi Additive for MgB2-Based Reactive Hydride Composites with Superior Kinetic Properties. The Journal of Physical Chemistry C. 2018. vol. 122, no. 14, 7642-7655. DOI: 10.1021/acs.jpcc.8b01850}} @misc{strmer_coatings_for_2018, author={Störmer, M., Siewert, F., Horstmann, C., Buchheim, J., Gwalt, G.}, title={Coatings for FEL optics: preparation and characterization of B4C and Pt}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S1600577517016095}, abstract = {Large X-ray mirrors are required for beam transport at both present-day and future free-electron lasers (FELs) and synchrotron sources worldwide. The demand for large mirrors with lengths up to 1 m single layers consisting of light or heavy elements has increased during the last few decades. Accordingly, surface finishing technology is now able to produce large substrate lengths with micro-roughness on the sub-nanometer scale. At the Helmholtz-Zentrum Geesthacht (HZG), a 4.5 m-long sputtering facility enables us to deposit a desired single-layer material some tens of nanometers thick. For the European XFEL project, the shape error should be less than 2 nm over the whole 1 m X-ray mirror length to ensure the safe and efficient delivery of X-ray beams to the scientific instruments. The challenge is to achieve thin-film deposition on silicon substrates, benders and gratings without any change in mirror shape. Thin films of boron carbide and platinum with a thickness in the range 30–100 nm were manufactured using the HZG sputtering facility. This setup is able to cover areas of up to 1500 mm × 120 mm in one step using rectangular sputtering sources. The coatings produced were characterized using various thin-film methods. It was possible to improve the coating process to achieve a very high uniformity of the layer thickness. The movement of the substrate in front of the sputtering source has been optimized. A variation in B4C layer thickness below 1 nm (peak-to-valley) was achieved at a mean thickness of 51.8 nm over a deposition length of 1.5 m. In the case of Pt, reflectometry and micro-roughness measurements were performed. The uniformity in layer thickness was about 1 nm (peak-to-valley). The micro-roughness of the Pt layers showed no significant change in the coated state for layer thicknesses of 32 nm and 102 nm compared with the uncoated substrate state. The experimental results achieved will be discussed with regard to current restrictions and future developments.}, note = {Online available at: \url{https://doi.org/10.1107/S1600577517016095} (DOI). Störmer, M.; Siewert, F.; Horstmann, C.; Buchheim, J.; Gwalt, G.: Coatings for FEL optics: preparation and characterization of B4C and Pt. Journal of Synchrotron Radiation. 2018. vol. 25, no. 1, 116-122. DOI: 10.1107/S1600577517016095}} @misc{makhotkin_experimental_study_2018, author={Makhotkin, I.A., Sobierajski, R., Chalupský, J., Tiedtke, K., De Vries, G., Störmer, M., Scholze, F., Siewert, F., Van De Kruijs, R.W.E., Milov, I., Louis, E., Jacyna, I., Jurek, M., Klinger, D., Nittler, L., Syryanyy, Y., Juha, L., Hájková, V., Vozda, V., Burian, T., Saksl, K., Faatz, B., Keitel, B., Plönjes, E., Schreiber, S., Toleikis, S., Loch, R., Hermann, M., Strobel, S., Nienhuys, H.-K., Gwalt, G., Mey, T., Enkisch, H.}, title={Experimental study of EUV mirror radiation damage resistance under long-term free-electron laser exposures below the single-shot damage threshold}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S1600577517017362}, abstract = {The durability of grazing- and normal-incidence optical coatings has been experimentally assessed under free-electron laser irradiation at various numbers of pulses up to 16 million shots and various fluence levels below 10% of the single-shot damage threshold. The experiment was performed at FLASH, the Free-electron LASer in Hamburg, using 13.5 nm extreme UV (EUV) radiation with 100 fs pulse duration. Polycrystalline ruthenium and amorphous carbon 50 nm thin films on silicon substrates were tested at total external reflection angles of 20° and 10° grazing incidence, respectively. Mo/Si periodical multilayer structures were tested in the Bragg reflection condition at 16° off-normal angle of incidence. The exposed areas were analysed post-mortem using differential contrast visible light microscopy, EUV reflectivity mapping and scanning X-ray photoelectron spectroscopy. The analysis revealed that Ru and Mo/Si coatings exposed to the highest dose and fluence level show a few per cent drop in their EUV reflectivity, which is explained by EUV-induced oxidation of the surface.}, note = {Online available at: \url{https://doi.org/10.1107/S1600577517017362} (DOI). Makhotkin, I.; Sobierajski, R.; Chalupský, J.; Tiedtke, K.; De Vries, G.; Störmer, M.; Scholze, F.; Siewert, F.; Van De Kruijs, R.; Milov, I.; Louis, E.; Jacyna, I.; Jurek, M.; Klinger, D.; Nittler, L.; Syryanyy, Y.; Juha, L.; Hájková, V.; Vozda, V.; Burian, T.; Saksl, K.; Faatz, B.; Keitel, B.; Plönjes, E.; Schreiber, S.; Toleikis, S.; Loch, R.; Hermann, M.; Strobel, S.; Nienhuys, H.; Gwalt, G.; Mey, T.; Enkisch, H.: Experimental study of EUV mirror radiation damage resistance under long-term free-electron laser exposures below the single-shot damage threshold. Journal of Synchrotron Radiation. 2018. vol. 25, no. 1, 77-84. DOI: 10.1107/S1600577517017362}} @misc{milov_mechanism_of_2018, author={Milov, I., Makhotkin, I.A., Sobierajski, R., Medvedev, N., Lipp, V., Chalupský, J., Sturm, J.M., Tiedtke, K., de Vries, G., Störmer, M., Siewert, F., van de Kruijs, R., Louis, E., Jacyna, I., Jurek, M., Juha, L., Hájková, V., Vozda, V., Burian, T., Saksl, K., Faatz, B., Keitel, B., Plönjes, E., Schreiber, S., Toleikis, S., Loch, R., Hermann, M., Strobel, S., Nienhuys, H.-K., Gwalt, G., Mey, T., Enkisch, H., Bijkerk, F.}, title={Mechanism of single-shot damage of Ru thin films irradiated by femtosecond extreme UV free-electron laser}, year={2018}, howpublished = {journal article}, doi = {https://doi.org/10.1364/OE.26.019665}, abstract = {Ruthenium is a perspective material to be used for XUV mirrors at free-electron laser facilities. Yet, it is still poorly studied in the context of ultrafast laser-matter interaction. In this work, we present single-shot damage studies of thin Ru films irradiated by femtosecond XUV free-electron laser pulses at FLASH. Ex-situ analysis of the damaged spots, performed by different types of microscopy, shows that the weakest detected damage is surface roughening. For higher fluences we observe ablation of Ru. Combined simulations using Monte-Carlo code XCASCADE(3D) and the two-temperature model reveal that the damage mechanism is photomechanical spallation, similar to the case of irradiating the target with optical lasers. The analogy with the optical damage studies enables us to explain the observed damage morphologies.}, note = {Online available at: \url{https://doi.org/10.1364/OE.26.019665} (DOI). Milov, I.; Makhotkin, I.; Sobierajski, R.; Medvedev, N.; Lipp, V.; Chalupský, J.; Sturm, J.; Tiedtke, K.; de Vries, G.; Störmer, M.; Siewert, F.; van de Kruijs, R.; Louis, E.; Jacyna, I.; Jurek, M.; Juha, L.; Hájková, V.; Vozda, V.; Burian, T.; Saksl, K.; Faatz, B.; Keitel, B.; Plönjes, E.; Schreiber, S.; Toleikis, S.; Loch, R.; Hermann, M.; Strobel, S.; Nienhuys, H.; Gwalt, G.; Mey, T.; Enkisch, H.; Bijkerk, F.: Mechanism of single-shot damage of Ru thin films irradiated by femtosecond extreme UV free-electron laser. Optics express. 2018. vol. 26, no. 15, 19665-19685. DOI: 10.1364/OE.26.019665}} @misc{paskevecius_metal_borohydrides_2017, author={Paskevecius, M., Jepsen, L.H., Schouwink, P., Cerny, R., Ravnsbaek, D.B., Filinchuk, Y., Dornheim, M., Besenbacher, F., Jensen, T.R.}, title={Metal borohydrides and derivatives - synthesis, structure and properties}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c6cs00705h}, abstract = {A wide variety of metal borohydrides, MBH4, have been discovered and characterized during the past decade, revealing an extremely rich chemistry including fascinating structural flexibility and a wide range of compositions and physical properties. Metal borohydrides receive increasing interest within the energy storage field due to their extremely high hydrogen density and possible uses in batteries as solid state ion conductors. Recently, new types of physical properties have been explored in lanthanide-bearing borohydrides related to solid state phosphors and magnetic refrigeration. Two major classes of metal borohydride derivatives have also been discovered: anion-substituted compounds where the complex borohydride anion, BH4−, is replaced by another anion, i.e. a halide or amide ion; and metal borohydrides modified with neutral molecules, such as NH3, NH3BH3, N2H4, etc. Here, we review new synthetic strategies along with structural, physical and chemical properties for metal borohydrides, revealing a number of new trends correlating composition, structure, bonding and thermal properties. These new trends provide general knowledge and may contribute to the design and discovery of new metal borohydrides with tailored properties towards the rational design of novel functional materials. This review also demonstrates that there is still room for discovering new combinations of light elements including boron and hydrogen, leading to complex hydrides with extreme flexibility in composition, structure and properties.}, note = {Online available at: \url{https://doi.org/10.1039/c6cs00705h} (DOI). Paskevecius, M.; Jepsen, L.; Schouwink, P.; Cerny, R.; Ravnsbaek, D.; Filinchuk, Y.; Dornheim, M.; Besenbacher, F.; Jensen, T.: Metal borohydrides and derivatives - synthesis, structure and properties. Chemical Society Reviews. 2017. vol. 46, no. 5, 1565-1634. DOI: 10.1039/c6cs00705h}} @misc{cao_transition_and_2017, author={Cao, H., Guo, J., Chang, F., Pistidda, C., Zhou, W., Zhang, X., Santoru, A., Wu, H., Schell, N., Niewa, R., Chen, P., Klassen, T., Dornheim, M.}, title={Transition and Alkali Metal Complex Ternary Amides for Ammonia Synthesis and Decomposition}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1002/chem.201702728}, abstract = {A new complex ternary amide, Rb2[Mn(NH2)4], which simultaneously contains both transition and alkali metal catalytic sites, is developed. This is in line with the recently reported TM-LiH composite catalysts, which have been shown to effectively break the scaling relations and achieve ammonia synthesis under mild conditions. Rb2[Mn(NH2)4] can be facilely synthesized by mechanochemical reaction at room temperature. It exhibits two temperature-dependent polymorphs, that is, a low-temperature orthorhombic and a high-temperature monoclinic structure. Rb2[Mn(NH2)4] decomposes to N2, H2, NH3, Mn3N2, and RbNH2 under inert atmosphere; whereas it releases NH3 at a temperature as low as 80 °C under H2 atmosphere. Those unique behaviors enable Rb2[Mn(NH2)4], and its analogue K2[Mn(NH2)4], to be excellent catalytic materials for ammonia decomposition and synthesis. Experimental results show both ammonia decomposition onset temperatures and conversion rates over Rb2[Mn(NH2)4] and K2[Mn(NH2)4] are similar to those of noble metal Ru-based catalysts. More importantly, these ternary amides exhibit superior capabilities in catalyzing NH3 synthesis, which are more than 3 orders of magnitude higher than that of Mn nitride and twice of that of Ru/MgO. The in situ SR-PXD measurement shows that manganese nitride, synergistic with Rb/KH or Rb/K(NH2)xH1−x, are likely the active sites. The chemistry of Rb2/K2[Mn(NH2)x] and Rb/K(NH2)xH1−x with H2/N2 and NH3 correlates closely with the catalytic performance.}, note = {Online available at: \url{https://doi.org/10.1002/chem.201702728} (DOI). Cao, H.; Guo, J.; Chang, F.; Pistidda, C.; Zhou, W.; Zhang, X.; Santoru, A.; Wu, H.; Schell, N.; Niewa, R.; Chen, P.; Klassen, T.; Dornheim, M.: Transition and Alkali Metal Complex Ternary Amides for Ammonia Synthesis and Decomposition. Chemistry - A European Journal. 2017. vol. 23, no. 41, 9766-9771. DOI: 10.1002/chem.201702728}} @misc{cao_the_effect_2017, author={Cao, H., Wang, H., Pistidda, C., Milanese, C., Zhang, W., Chaudhary, A.-L., Santoru, A., Garroni, S., Bednarcik, J., Liermann, H.-P., Chen, P., Klassen, T., Dornheim, M.}, title={The effect of Sr(OH)2 on the hydrogen storage properties of the Mg(NH2)2–2LiH system}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1039/C7CP00748E}, abstract = {The doping effect of Sr(OH)2 on the Mg(NH2)2–2LiH system is investigated considering different amounts of added Sr(OH)2 in the range of 0.05 to 0.2 mol. Experimental results show that both the thermodynamic and the kinetic properties of Mg(NH2)2–2LiH are influenced by the presence of Sr(OH)2. The addition of 0.1 mol Sr(OH)2 leads to a decrease in both the dehydrogenation onset and peak temperatures of ca. 70 and 13 °C, respectively, and an acceleration in the de/re-hydrogenation rates of one time at 150 °C compared to Mg(NH2)2–2LiH alone. Based on differential scanning calorimetry (DSC) analysis, the overall reaction enthalpy of the 0.1 Sr(OH)2-doped sample is calculated to be 44 kJ per mol-H2 and there are two absorption events occurring in the doped sample instead of one in the pristine sample. For the applied experimental conditions, according to the in situ synchrotron radiation powder X-ray diffraction (SR-PXD) and Fourier Transform Infrared spectroscopy (FT-IR) analysis, the reaction mechanism has been finally defined: Sr(OH)2, Mg(NH2)2 and LiH react with each other to form SrO, MgO and LiNH2 during ball milling. After heating, SrO interacts with Mg(NH2)2 producing MgO and Sr(NH2)2. Then Mg(NH2)2, LiNH2 and Sr(NH2)2 react with LiH to produce Li2NH, SrNH, Li2Mg(NH)2 and Li2Mg2(NH)3 in traces. After re-hydrogenation, LiSrH3, LiH and LiNH2 are formed along with amorphous Mg(NH2)2. The reasons for the improved kinetics are: (a) during dehydrogenation, the in situ formation of SrNH appears to increase the interfacial contacts between Mg(NH2)2 and LiH and also weakens the N–H bond of Mg(NH2)2; (b) during absorption, the formation of LiSrH3 at around 150 °C could be the key factor for improving the hydrogenation properties.}, note = {Online available at: \url{https://doi.org/10.1039/C7CP00748E} (DOI). Cao, H.; Wang, H.; Pistidda, C.; Milanese, C.; Zhang, W.; Chaudhary, A.; Santoru, A.; Garroni, S.; Bednarcik, J.; Liermann, H.; Chen, P.; Klassen, T.; Dornheim, M.: The effect of Sr(OH)2 on the hydrogen storage properties of the Mg(NH2)2–2LiH system. Physical Chemistry Chemical Physics. 2017. vol. 19, no. 12, 8457-8464. DOI: 10.1039/C7CP00748E}} @misc{carillobucio_hydrogenation_study_2017, author={Carillo-Bucio, J.L., Saldan, I., Pistidda, C., Karimi, F., Suarez-Alcantara, K., Dornheim, M., Klassen, T.}, title={Hydrogenation Study of NaF/NaH/MgB2 Reactive Hydride Composites}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.jpcc.6b09776}, abstract = {The hydrogenation of NaF/9NaH + 5MgB2 and NaF/2NaH + 1.5MgB2 reactive hydride composites (RHC) was studied by volumetric titration (kinetics and PCI curves), in situ synchrotron radiation powder X-ray diffraction (SR-PXD), high-pressure differential scanning calorimetry (HP-DSC), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM). A hydrogen uptake between 4.1 and 4.8 wt % was observed when the H2 pressure was in the range between 25 and 50 bar, and the temperature was kept constant at 325 °C. PCI curves indicate a hydrogenation equilibrium pressure of 2 and 8 bar at 325 °C for NaF/9NaH + 5MgB2 and NaF/2NaH + 1.5MgB2, respectively. Synchrotron radiation powder X-ray diffraction revealed the formation of solid solutions of NaF–NaH after milling and a change in the reaction pathway compared to a reported nondoped 2NaH + MgB2 reactive hydride composite. Formation of the stable side-product NaMgH2F was found as a drawback for hydrogen storage capacity and reversibility. FT-IR indicates no hydrogen to fluorine substitution in the NaBH4 product.}, note = {Online available at: \url{https://doi.org/10.1021/acs.jpcc.6b09776} (DOI). Carillo-Bucio, J.; Saldan, I.; Pistidda, C.; Karimi, F.; Suarez-Alcantara, K.; Dornheim, M.; Klassen, T.: Hydrogenation Study of NaF/NaH/MgB2 Reactive Hydride Composites. The Journal of Physical Chemistry C. 2017. vol. 121, no. 8, 4093-4102. DOI: 10.1021/acs.jpcc.6b09776}} @misc{cao_in_situ_2017, author={Cao, H., Pistidda, C., Richter, T.M.M., Santoru, A., Milanese, C., Garroni, S., Bednarcik, J., Chaudhary, A.-L., Gizer, G., Liermann, H.-P., Niewa, R., Ping, C., Klassen, T., Dornheim, M.}, title={In Situ X-ray Diffraction Studies on the De/rehydrogenation Processes of the K2[Zn(NH2)4]-8LiH System}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.jpcc.6b12095}, abstract = {In this work, the hydrogen absorption and desorption properties of the system K2[Zn(NH2)4]-8LiH are investigated in detail via in situ synchrotron radiation powder X-ray diffraction (SR-PXD), Fourier transform infrared spectroscopy (FT-IR), and volumetric methods. Upon milling, K2[Zn(NH2)4] and 8LiH react to form 4LiNH2-4LiH-K2ZnH4, and then 4LiNH2-4LiH-K2ZnH4 releases H2 in multiple steps. The final products of the desorption reaction are KH, LiZn13, and Li2NH. During rehydrogenation, KH reacts with LiZn13 under 50 bar of hydrogen producing K3ZnH5. This phase appears to enhance the hydrogenation process which after its formation at ca. 220 °C takes place in only 30 s. The system 4LiNH2-4LiH-K2ZnH4 is shown to be reversible under the applied conditions of vacuum at 400 °C for desorption and 50 bar of H2 at 300 °C for absorption.}, note = {Online available at: \url{https://doi.org/10.1021/acs.jpcc.6b12095} (DOI). Cao, H.; Pistidda, C.; Richter, T.; Santoru, A.; Milanese, C.; Garroni, S.; Bednarcik, J.; Chaudhary, A.; Gizer, G.; Liermann, H.; Niewa, R.; Ping, C.; Klassen, T.; Dornheim, M.: In Situ X-ray Diffraction Studies on the De/rehydrogenation Processes of the K2[Zn(NH2)4]-8LiH System. The Journal of Physical Chemistry C. 2017. vol. 121, no. 3, 1546-1551. DOI: 10.1021/acs.jpcc.6b12095}} @misc{puszkiel_changing_the_2017, author={Puszkiel, J.A., Castro Riglos, M.V., Karimi, F., Santoru, A., Pistidda, C., Klassen, T., Bellosta von Colbe, J.M., Dornheim, M.}, title={Changing the dehydrogenation pathway of LiBH4–MgH2 via nanosized lithiated TiO2}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1039/C6CP08278E}, abstract = {Nanosized lithiated titanium oxide (LixTiO2) noticeably improves the kinetic behaviour of 2LiBH4 + MgH2. The presence of LixTiO2 reduces the time required for the first dehydrogenation by suppressing the intermediate reaction to Li2B12H12, leading to direct MgB2 formation.}, note = {Online available at: \url{https://doi.org/10.1039/C6CP08278E} (DOI). Puszkiel, J.; Castro Riglos, M.; Karimi, F.; Santoru, A.; Pistidda, C.; Klassen, T.; Bellosta von Colbe, J.; Dornheim, M.: Changing the dehydrogenation pathway of LiBH4–MgH2 via nanosized lithiated TiO2. Physical Chemistry Chemical Physics. 2017. vol. 19, no. 11, 7455-7460. DOI: 10.1039/C6CP08278E}} @misc{dong_thermal_optimisation_2017, author={Dong, D., Humphries, T.D., Sheppard, D.A., Stansby, B., Paskevicius, M., Sofianos, M.V., Chaudhary, A.-L., Dornheim, M., Buckley, C.E.}, title={Thermal optimisation of metal hydride reactors for thermal energy storage applications}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1039/C7SE00316A}, abstract = {Metal hydrides (MHs) are promising candidates as thermal energy storage (TES) materials for concentrated solar thermal applications. A key requirement for this technology is a high temperature heat transfer fluid (HTF) that can deliver heat to the MHs for storage during the day, and remove heat at night time to produce electricity. In this study, supercritical water was used as a HTF to heat a prototype thermochemical heat storage reactor filled with MgH2 powder during H2 sorption, rather than electrical heating of the MH reactor. This is beneficial as the HTF flows through a coil of tubing embedded within the MH bed and is hence in better contact with the MgH2 powder. This internal heating mode produces a more uniform temperature distribution within the reactor by increasing the heat exchange surface area and reducing the characteristic heat exchange distances. Moreover, supercritical water can be implemented as a heat carrier for the entire thermal energy system within a concentrating solar thermal plant, from the receiver, through the heat storage system, and also within a conventional turbine-driven electric power generation system. Thus, the total system energy efficiency can be improved by minimising HTF heat exchangers.}, note = {Online available at: \url{https://doi.org/10.1039/C7SE00316A} (DOI). Dong, D.; Humphries, T.; Sheppard, D.; Stansby, B.; Paskevicius, M.; Sofianos, M.; Chaudhary, A.; Dornheim, M.; Buckley, C.: Thermal optimisation of metal hydride reactors for thermal energy storage applications. Sustainable Energy and Fuels. 2017. vol. 1, no. 8, 1820-1829. DOI: 10.1039/C7SE00316A}} @misc{garroni_mechanically_activated_2017, author={Garroni, S., Delogu, F., Bonatto, Minella, C., Pistidda, C., Cuesta-Lopez, S.}, title={Mechanically activated metathesis reaction in NaNH2–MgH2 powder mixtures}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s10853-017-1220-5}, abstract = {The present work addresses the kinetics of chemical transformations activated by the mechanical processing of powder by ball milling. In particular, attention focuses on the reaction between NaNH2 and MgH2, specific case studies suitably chosen to throw light on the kinetic features emerging in connection with the exchange of anionic ligands induced by mechanical activation. Experimental findings indicate that the mechanical treatment of NaNH2–MgH2 powder mixtures induces a simple metathetic reaction with formation of NaH and Mg(NH2)2 phases. Chemical conversion data obtained by X-ray diffraction analysis have been interpreted using a kinetic model incorporating the statistical character of the mechanical processing by ball milling. The apparent rate constant measuring the reaction rate is related to the volume of powder effectively processed during individual collisions, and tentatively connected with the transfer of mechanical energy across the network formed by the points of contact between the powder particles trapped during collisions.}, note = {Online available at: \url{https://doi.org/10.1007/s10853-017-1220-5} (DOI). Garroni, S.; Delogu, F.; Bonatto, M.; Pistidda, C.; Cuesta-Lopez, S.: Mechanically activated metathesis reaction in NaNH2–MgH2 powder mixtures. Journal of Materials Science. 2017. vol. 52, no. 20, 11891-11899. DOI: 10.1007/s10853-017-1220-5}} @misc{wang_effects_of_2017, author={Wang, H., Cao, H., Pistidda, C., Garroni, S., Wu, G., Klassen, T., Dornheim, M., Chen, P.}, title={Effects of Stoichiometry on the H2-Storage Properties of Mg(NH2)2–LiH–LiBH4 Tri-Component Systems}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1002/asia.201700287}, abstract = {The hydrogen desorption pathways and storage properties of 2 Mg(NH2)2–3 LiH–xLiBH4 samples (x=0, 1, 2, and 4) were investigated systematically by a combination of pressure composition isotherm (PCI), differential scanning calorimetric (DSC), and volumetric release methods. Experimental results showed that the desorption peak temperatures of 2 Mg(NH2)2–3 LiH–xLiBH4 samples were approximately 10–15 °C lower than that of 2 Mg(NH2)2–3 LiH. The 2 Mg(NH2)2–3 LiH–4 LiBH4 composite in particular began to release hydrogen at 90 °C, thereby exhibiting superior dehydrogenation performance. All of the LiBH4-doped samples could be fully dehydrogenated and re-hydrogenated at a temperature of 143 °C. The high hydrogen pressure region (above 50 bar) of PCI curves for the LiBH4-doped samples rose as the amount of LiBH4 increased. LiBH4 changed the desorption pathway of the 2 Mg(NH2)2–3 LiH sample under a hydrogen pressure of 50 bar, thereby resulting in the formation of MgNH and molten [LiNH2–2 LiBH4]. That is different from the dehydrogenation pathway of 2 Mg(NH2)2–3 LiH sample without LiBH4, which formed Li2Mg2N3H3 and LiNH2, as reported previously. In addition, the results of DSC analyses showed that the doped samples exhibited two independent endothermic events, which might be related to two different desorption pathways.}, note = {Online available at: \url{https://doi.org/10.1002/asia.201700287} (DOI). Wang, H.; Cao, H.; Pistidda, C.; Garroni, S.; Wu, G.; Klassen, T.; Dornheim, M.; Chen, P.: Effects of Stoichiometry on the H2-Storage Properties of Mg(NH2)2–LiH–LiBH4 Tri-Component Systems. Chemistry : An Asian Journal. 2017. vol. 12, no. 14, 1758-1764. DOI: 10.1002/asia.201700287}} @misc{gawlik_the_effects_2017, author={Gawlik, M.M., Steiner, M., Wiese, B., Gonzalez, J., Feyerabend, F., Dahms, M., Ebel, T., Willumeit-Roemer, R.}, title={The Effects of HAc Etching on the Degradation Behavior of Mg-5Gd}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.24354/medmat.v1i2.17}, abstract = {The effects of different acetic acid (HAc) etching procedures were investigated using Mg-5Gd samples in as-extruded and T4 conditions in order to achieve defined surfaces and homogenous degradation behavior. Samples were dipped into HAc solution with five different concentrations for three durations. In total, fifteen different etching conditions were tested with regard to the degradation resistance in physiological solution. The cell culture medium consisted of Dulbecco's Modified Eagle Medium (DMEM), Glutamax, 10 Vol.-% fetal bovine serum (FBS) and 1 Vol.-% Streptomycin/Penicillin solution. A screening test was performed to select the etching combinations with the lowest initial mean degradation depth. The most promising etching procedures were chosen for further long term degradation tests lasting up to 30 days in cell culture medium. The surfaces of the etched samples and for selected samples after degradation were characterized by interferometry, OM, SEM, and XRD to correlate the influence of morphology, roughness and microstructure on the degradation rate. Etching with 250 g/L HAc and 150 s leads to the most uniform degradation with low degradation rate compared to non-etched Mg-5Gd.}, note = {Online available at: \url{https://doi.org/10.24354/medmat.v1i2.17} (DOI). Gawlik, M.; Steiner, M.; Wiese, B.; Gonzalez, J.; Feyerabend, F.; Dahms, M.; Ebel, T.; Willumeit-Roemer, R.: The Effects of HAc Etching on the Degradation Behavior of Mg-5Gd. Journal of Medical Materials and Technologies. 2017. vol. 1, no. 2, 22-25. DOI: 10.24354/medmat.v1i2.17}} @misc{puszkiel_a_novel_2017, author={Puszkiel, J.A., Castro Riglos, M.V., Ramallo-Lopez, J.M., Mizrahi, M., Karimi, F., Santoru, A., Hoell, A., Gennari, F.C., Arneodo Larochette, P., Pistidda, C., Klassen, T., Bellosta von Colbe J.M., Dornheim, M.}, title={A novel catalytic route for hydrogenation–dehydrogenation of 2LiH + MgB2via in situ formed core–shell LixTiO2 nanoparticles}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c7ta03117c}, abstract = {Aiming to improve the hydrogen storage properties of 2LiH + MgB2 (Li-RHC), the effect of TiO2 addition to Li-RHC is investigated. The presence of TiO2 leads to the in situ formation of core–shell LixTiO2 nanoparticles during milling and upon heating. These nanoparticles markedly enhance the hydrogen storage properties of Li-RHC. Throughout hydrogenation–dehydrogenation cycling at 400 °C a 1 mol% TiO2 doped Li-RHC material shows sustainable hydrogen capacity of ∼10 wt% and short hydrogenation and dehydrogenation times of just 25 and 50 minutes, respectively. The in situ formed core–shell LixTiO2 nanoparticles confer proper microstructural refinement to the Li-RHC, thus preventing the material's agglomeration upon cycling. An analysis of the kinetic mechanisms shows that the presence of the core–shell LixTiO2 nanoparticles accelerates the one-dimensional interface-controlled mechanism during hydrogenation owing to the high Li+ mobility through the LixTiO2 lattice. Upon dehydrogenation, the in situ formed core–shell LixTiO2 nanoparticles do not modify the dehydrogenation thermodynamic properties of the Li-RHC itself. A new approach by the combination of two kinetic models evidences that the activation energy of both MgH2 decomposition and MgB2 formation is reduced. These improvements are due to a novel catalytic mechanism via Li+ source/sink reversible reactions.}, note = {Online available at: \url{https://doi.org/10.1039/c7ta03117c} (DOI). Puszkiel, J.; Castro Riglos, M.; Ramallo-Lopez, J.; Mizrahi, M.; Karimi, F.; Santoru, A.; Hoell, A.; Gennari, F.; Arneodo Larochette, P.; Pistidda, C.; Klassen, T.; Bellosta von Colbe J.M.; Dornheim, M.: A novel catalytic route for hydrogenation–dehydrogenation of 2LiH + MgB2via in situ formed core–shell LixTiO2 nanoparticles. Journal of Materials Chemistry A. 2017. vol. 5, no. 25, 12922-12933. DOI: 10.1039/c7ta03117c}} @misc{li_thermodynamic_properties_2017, author={Li, G., Matsuo, M., Takagi, S., Chaudhary, A.-L., Sato, T., Dornheim, M., Orimo, S.-I.}, title={Thermodynamic Properties and Reversible Hydrogenation of LiBH4–Mg2FeH6 Composite Materials}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.3390/inorganics5040081}, abstract = {In previous studies, complex hydrides LiBH4 and Mg2FeH6 have been reported to undergo simultaneous dehydrogenation when ball-milled as composite materials (1 − x)LiBH4 + xMg2FeH6. The simultaneous hydrogen release led to a decrease of the dehydrogenation temperature by as much as 150 K when compared to that of LiBH4. It also led to the modified dehydrogenation properties of Mg2FeH6. The simultaneous dehydrogenation behavior between stoichiometric ratios of LiBH4 and Mg2FeH6 is not yet understood. Therefore, in the present work, we used the molar ratio x = 0.25, 0.5, and 0.75, and studied the isothermal dehydrogenation processes via pressure–composition–isothermal (PCT) measurements. The results indicated that the same stoichiometric reaction occurred in all of these composite materials, and x = 0.5 was the molar ratio between LiBH4 and Mg2FeH6 in the reaction. Due to the optimal composition ratio, the composite material exhibited enhanced rehydrogenation and reversibility properties: the temperature and pressure of 673 K and 20 MPa of H2, respectively, for the full rehydrogenation of x = 0.5 composite, were much lower than those required for the partial rehydrogenation of LiBH4. Moreover, the x = 0.5 composite could be reversibly hydrogenated for more than four cycles without degradation of its H2 capacity.}, note = {Online available at: \url{https://doi.org/10.3390/inorganics5040081} (DOI). Li, G.; Matsuo, M.; Takagi, S.; Chaudhary, A.; Sato, T.; Dornheim, M.; Orimo, S.: Thermodynamic Properties and Reversible Hydrogenation of LiBH4–Mg2FeH6 Composite Materials. Inorganics. 2017. vol. 5, no. 4, 81. DOI: 10.3390/inorganics5040081}} @misc{zhang_effects_of_2017, author={Zhang, W., Wang, H., Cao, H., He, T., Guo, J., Wu, G., Chen, P.}, title={Effects of doping FeCl3 on hydrogen storage properties of Li-N-H system}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.pnsc.2016.12.017}, abstract = {The effects of doping FeCl3 on the LiNH2−2LiH system were investigated systematically. FeCl3 was prior to react with LiH during ball milling their mixtures. The metallic Fe, which is generated from metathesis reaction between FeCl3 and LiH, plays an important role on improving the dehydrogenation kinetics of LiNH2−2LiH system. The results indicated that the dehydrogenation peak and ending temperatures of the doped 1 mol% FeCl3 sample shifted to low temperatures, and the dehydrogenation active energy changed from 102.45 kJ/mol to 87.52 kJ/mol. While increasing the amount of FeCl3, an excess of LiCl, the by-product of metathesis reaction between FeCl3 and LiH, can stabilize LiNH2 and thus hinder hydrogen desorption. The dehydrogenation product is a new solid cubic phase solution of lithium imide-chloride. The high limit of the solid solution of LiCl and Li2NH is near the molar ratio of 1:1.}, note = {Online available at: \url{https://doi.org/10.1016/j.pnsc.2016.12.017} (DOI). Zhang, W.; Wang, H.; Cao, H.; He, T.; Guo, J.; Wu, G.; Chen, P.: Effects of doping FeCl3 on hydrogen storage properties of Li-N-H system. Progress in Natural Science: Materials International. 2017. vol. 27, no. 1, 139-143. DOI: 10.1016/j.pnsc.2016.12.017}} @misc{toufarov_contrasting_behavior_2017, author={Toufarová, M., Hájková, V., Chalupský, J., Burian, T., Vacík, J., Vorlícek, V., Vyšín, L., Gaudin, J., Medvedev, N., Ziaja, B., Nagasono, M., Yabashi, M., Sobierajski, R., Krzywinski, J., Sinn, H., Störmer, M., Kolácek, K., Tiedtke, K., Toleikis, S., Juha, L.}, title={Contrasting behavior of covalent and molecular carbon allotropes exposed to extreme ultraviolet and soft x-ray free-electron laser radiation}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1103/PhysRevB.96.214101}, abstract = {All carbon materials, e.g., amorphous carbon (a-C) coatings and C60 fullerene thin films, play an important role in short-wavelength free-electron laser (FEL) research motivated by FEL optics development and prospective nanotechnology applications. Responses of a-C and C60 layers to the extreme ultraviolet (SPring-8 Compact SASE Source in Japan) and soft x-ray (free-electron laser in Hamburg) free-electron laser radiation are investigated by Raman spectroscopy, differential interference contrast, and atomic force microscopy. A remarkable difference in the behavior of covalent (a-C) and molecular (C60) carbonaceous solids is demonstrated under these irradiation conditions. Low thresholds for ablation of a fullerene crystal (estimated to be around 0.15 eV/atom for C60 vs 0.9 eV/atom for a-C in terms of the absorbed dose) are caused by a low cohesive energy of fullerene crystals. An efficient mechanism of the removal of intact C60 molecules from the irradiated crystal due to Coulomb repulsion of fullerene-cage cation radicals formed by the ionizing radiation is revealed by a detailed modeling.}, note = {Online available at: \url{https://doi.org/10.1103/PhysRevB.96.214101} (DOI). Toufarová, M.; Hájková, V.; Chalupský, J.; Burian, T.; Vacík, J.; Vorlícek, V.; Vyšín, L.; Gaudin, J.; Medvedev, N.; Ziaja, B.; Nagasono, M.; Yabashi, M.; Sobierajski, R.; Krzywinski, J.; Sinn, H.; Störmer, M.; Kolácek, K.; Tiedtke, K.; Toleikis, S.; Juha, L.: Contrasting behavior of covalent and molecular carbon allotropes exposed to extreme ultraviolet and soft x-ray free-electron laser radiation. Physical Review B. 2017. vol. 96, no. 21, 214101. DOI: 10.1103/PhysRevB.96.214101}} @misc{chaudhary_synthesis_of_2017, author={Chaudhary, A.-L., Dietzel, S., Li, H.-W., Akiba, E., Bergemann, N., Pistidda, C., Klassen, T., Dornheim, M.}, title={Synthesis of Mg2FeD6 under low pressure conditions for Mg2FeH6 hydrogen storage studies}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2017.02.033}, abstract = {Mg2FeD6 is successfully synthesised with various degrees of purity using reactive ball milling and annealing under low pressure deuterium conditions to a maximum of 10 bar. The deuteride of the low cost ternary metal hydride Mg2FeH6, is synthesised to enable further characterisation studies such as isotopic exchange behaviour. Both on laboratory and industrial scales, keeping the pressure low reduces the need for expensive compression systems and also minimises the quantity of gas necessary for use; therefore it is important to assess synthesis under these cost effective conditions. This is especially the case when using a specialised gas such as high purity deuterium. The maximum pressure chosen is 10 bar, to comply with the High Pressure Safety Act in Japan. This Safety Act limits the use of any gas including hydrogen and deuterium to 10 bar eliminating the use of traditional synthesis methods for Mg2FeH6 or Mg2FeD6 synthesis at high pressure (120 bar). Ball milling parameters such as milling times, ball to powder ratios as well as sintering times were altered to achieve improved Mg2FeD6 yields under these low pressure conditions.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2017.02.033} (DOI). Chaudhary, A.; Dietzel, S.; Li, H.; Akiba, E.; Bergemann, N.; Pistidda, C.; Klassen, T.; Dornheim, M.: Synthesis of Mg2FeD6 under low pressure conditions for Mg2FeH6 hydrogen storage studies. International Journal of Hydrogen Energy. 2017. vol. 42, no. 16, 11422-11428. DOI: 10.1016/j.ijhydene.2017.02.033}} @misc{wang_near_ambient_2017, author={Wang, H., Wu, G., Cao, H., Pistidda, C., Chaudhary, A.-L., Garroni, S., Dornheim, M., Chen, P.}, title={Near Ambient Condition Hydrogen Storage in a Synergized Tricomponent Hydride System}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1002/aenm.201602456}, abstract = {Reversible hydrogen storage over hydrides of light elements (HLEs) under ambient condition has been pursued actively for nearly two decades. However, because of unfavorable thermodynamics and/or severe kinetic barrier of HLEs, limited progress has been made. Here, it is demonstrated that the interaction of LiBH4 with Mg(NH2)2 and LiH, three of the most investigated HLEs, can lead to a fully reversible dehydrogenation/rehydrogenation cycle at temperatures below 373 K. More importantly, with the desorption enthalpy of 24 kJ (mol H2)−1 the dehydrogenation process at 1.0 bar H2 is theoretically possible to be as low as 266 K. Characterization of this combination of HLEs shows that LiBH4 serves as a reagent complexing with intermediates and products of the dehydrogenation of Mg(NH2)2-LiH, and significantly alters the overall thermodynamic and kinetic properties of the system.}, note = {Online available at: \url{https://doi.org/10.1002/aenm.201602456} (DOI). Wang, H.; Wu, G.; Cao, H.; Pistidda, C.; Chaudhary, A.; Garroni, S.; Dornheim, M.; Chen, P.: Near Ambient Condition Hydrogen Storage in a Synergized Tricomponent Hydride System. Advanced Energy Materials. 2017. vol. 7, no. 13, 1602456. DOI: 10.1002/aenm.201602456}} @misc{puszkiel_tetrahydroborates_development_2017, author={Puszkiel, J., Garroni, S., Milanese, C., Gennari, F., Klassen, T., Dornheim, M., Pistidda, C.}, title={Tetrahydroborates: Development and Potential as Hydrogen Storage Medium}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.3390/inorganics5040074}, abstract = {The use of fossil fuels as an energy supply becomes increasingly problematic from the point of view of both environmental emissions and energy sustainability. As an alternative, hydrogen is widely regarded as a key element for a potential energy solution. However, different from fossil fuels such as oil, gas, and coal, the production of hydrogen requires energy. Alternative and intermittent renewable sources such as solar power, wind power, etc., present multiple advantages for the production of hydrogen. On one hand, the renewable sources contribute to a remarkable reduction of pollutants released to the air. On the other hand, they significantly enhance the sustainability of energy supply. In addition, the storage of energy in form of hydrogen has a huge potential to balance an effective and synergetic utilization of the renewable energy sources. In this regard, hydrogen storage technology presents a key roadblock towards the practical application of hydrogen as “energy carrier”. Among the methods available to store hydrogen, solid-state storage is the most attractive alternative both from the safety and the volumetric energy density points of view. Because of their appealing hydrogen content, complex hydrides and complex hydride-based systems have attracted considerable attention as potential energy vectors for mobile and stationary applications. In this review, the progresses made over the last century on the development in the synthesis and research on the decomposition reactions of homoleptic tetrahydroborates is summarized. Furthermore, theoretical and experimental investigations on the thermodynamic and kinetic tuning of tetrahydroborates for hydrogen storage purposes are herein reviewed.}, note = {Online available at: \url{https://doi.org/10.3390/inorganics5040074} (DOI). Puszkiel, J.; Garroni, S.; Milanese, C.; Gennari, F.; Klassen, T.; Dornheim, M.; Pistidda, C.: Tetrahydroborates: Development and Potential as Hydrogen Storage Medium. Inorganics. 2017. vol. 5, no. 4, 74. DOI: 10.3390/inorganics5040074}} @misc{nidadavolu_degradation_behavior_2017, author={Nidadavolu, E.P.S., Feyerabend, F., Ebel, T., Willumeit-Roemer, R., Dahms, M.}, title={Degradation behavior of as cast and powder metallurgy processed Mg-Ca alloys}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.24354/medmat.v1i2.19}, abstract = {Biodegradability and mechanical properties similar to natural bone have made Mg alloys potential competitors for metal implant applications. Mg-Ca alloys are of interest as Ca is an essential element in the human body. However, an increased Mg2Ca secondary phase with increasing Ca addition results in pitting corrosion in these alloys. Reports suggest that Mg alloys with ≤ 1wt % Ca additions possess good degradation resistance. Hence, Mg-xCa alloys (x= 0.3, 0.6, 0.9 wt %) were fabricated by gravity die chill casting and powder metallurgy (PM) techniques. Their ‘mean degradation depth, h (µm)’ values were measured by immersion test. Physiological cell-culture medium DMEM+ Glutamax with proteins (10% FBS) and an incubator were adopted for conducting the test. The volume fraction of Mg2Ca was calculated with Image J image analysis software. Results show that degradation behavior is influenced by the amount of secondary phase and its distribution in the Mg matrix. PM alloys showed homogenous degradation compared to the as cast alloys. The highest degradation resistance was exhibited by PM processed Mg-0.3Ca alloy with lowest h value of 0.39 µm. A long term immersion test revealed the ‘mean degradation rate, ḣ∞ (µm/day)’ as 0.51 µm/day.}, note = {Online available at: \url{https://doi.org/10.24354/medmat.v1i2.19} (DOI). Nidadavolu, E.; Feyerabend, F.; Ebel, T.; Willumeit-Roemer, R.; Dahms, M.: Degradation behavior of as cast and powder metallurgy processed Mg-Ca alloys. Journal of Medical Materials and Technologies. 2017. vol. 1, no. 2, 18-21. DOI: 10.24354/medmat.v1i2.19}} @misc{hansen_synthesis_structures_2017, author={Hansen, B.R.S., Tumanov, N., Santoru, A., Pistidda, C., Bednarcik, J., Klassen, T., Dornheim, M., Filinchuk, Y., Jensen, T.R.}, title={Synthesis, structures and thermal decomposition of ammine MxB12H12 complexes (M = Li, Na, Ca)}, year={2017}, howpublished = {journal article}, doi = {https://doi.org/10.1039/C7DT01414G}, abstract = {A series of ammine metal-dodecahydro-closo-dodecaboranes, MxB12H12·nNH3 (M = Li, Na, Ca) were synthesized and their structural and thermal properties studied with in situ time-resolved synchrotron radiation powder X-ray diffraction, thermal analysis, Fourier transformed infrared spectroscopy, and temperature-programmed photographic analysis. The synthesized compounds, Li2B12H12·7NH3, Na2B12H12·4NH3 and CaB12H12·6NH3, contain high amounts of NH3, 43.3, 26.6 and 35.9 wt% NH3, respectively, which can be released and absorbed reversibly at moderate conditions without decomposition, thereby making the closo-boranes favorable ‘host’ materials for ammonia or indirect hydrogen storage in the solid state. In this work, fifteen new ammine metal dodecahydro-closo-dodecaborane compounds are observed by powder X-ray diffraction, of which six are structurally characterized, Li2B12H12·4NH3, Li2B12H12·2NH3, Na2B12H12·4NH3, Na2B12H12·2NH3, CaB12H12·4NH3 and CaB12H12·3NH3. Li2B12H12·4NH3 and Na2B12H12·4NH3 are isostructural and monoclinic (P21/n) whereas Na2B12H12·2NH3 and CaB12H12·3NH3 are both trigonal with space groups Pm1 and Rc, respectively. Generally, coordination between the metal and the icosahedral closo-borane anion is diverse and includes point sharing, edge sharing, or face sharing, while coordination of ammonia always occurs via the lone pair on nitrogen to the metal. Furthermore, a liquid intermediate is observed during heating of Li2B12H12·7NH3. This work provides deeper insight into the structural, physical, and chemical properties related to thermal decomposition and possible ammonia and hydrogen storage.}, note = {Online available at: \url{https://doi.org/10.1039/C7DT01414G} (DOI). Hansen, B.; Tumanov, N.; Santoru, A.; Pistidda, C.; Bednarcik, J.; Klassen, T.; Dornheim, M.; Filinchuk, Y.; Jensen, T.: Synthesis, structures and thermal decomposition of ammine MxB12H12 complexes (M = Li, Na, Ca). Dalton Transactions. 2017. vol. 46, no. 24, 7770-7781. DOI: 10.1039/C7DT01414G}} @misc{brigo_mesoporous_silica_2016, author={Brigo, L., Scomparin, E., Galuppo, M., Capurso, G., Ferlin, M.G., Bello, V., Realdon, N., Brusatin, G., Morpurgo, M.}, title={Mesoporous silica sub-micron spheres as drug dissolution enhancers: Influence of drug and matrix chemistry on functionality and stability}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.msec.2015.10.039}, abstract = {Mesoporous silica particles prepared through a simplified Stöber method and low temperature solvent-promoted surfactant removal are evaluated as dissolution enhancers for poorly soluble compounds, using a powerful anticancer agent belonging to pyrroloquinolinones as a model for anticancer oral therapy, and anti-inflammatory ibuprofen as a reference compound. Mesoporous powders composed of either pure silica or silica modified with aminopropyl residues are produced. The influence of material composition and drug chemical properties on drug loading capability and dissolution enhancement are studied. The two types of particles display similar size, surface area, porosity, erodibility, drug loading capability and stability. An up to 50% w/w drug loading is reached, showing correlation between drug concentration in adsorption medium and content in the final powder. Upon immersion in simulating body fluids, immediate drug dissolution occurred, allowing acceptor solutions to reach concentrations equal to or greater than drug saturation limits. The matrix composition influenced drug solution maximal concentration, complementing the dissolution enhancement generated by a mesoporous structure. This effect was found to depend on both matrix and drug chemical properties allowing us to hypothesise general prediction behaviour rules.}, note = {Online available at: \url{https://doi.org/10.1016/j.msec.2015.10.039} (DOI). Brigo, L.; Scomparin, E.; Galuppo, M.; Capurso, G.; Ferlin, M.; Bello, V.; Realdon, N.; Brusatin, G.; Morpurgo, M.: Mesoporous silica sub-micron spheres as drug dissolution enhancers: Influence of drug and matrix chemistry on functionality and stability. Materials Science and Engineering C. 2016. vol. 59, 585-593. DOI: 10.1016/j.msec.2015.10.039}} @misc{sheppard_metal_hydrides_2016, author={Sheppard, D.A., Paskevicius, M., Humphries, T.D., Felderhoff, M., Capurso, G., Bellosta von Colbe, J., Dornheim, M., Klassem, T., Ward, P.A., Teprovich, J.A.Jr., Corgnale, C., Zidan, R., Grant, D.M., Buckley, C.E.}, title={Metal hydrides for concentrating solar thermal power energy storage}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s00339-016-9825-0}, abstract = {The development of alternative methods for thermal energy storage is important for improving the efficiency and decreasing the cost of concentrating solar thermal power. We focus on the underlying technology that allows metal hydrides to function as thermal energy storage (TES) systems and highlight the current state-of-the-art materials that can operate at temperatures as low as room temperature and as high as 1100 °C. The potential of metal hydrides for thermal storage is explored, while current knowledge gaps about hydride properties, such as hydride thermodynamics, intrinsic kinetics and cyclic stability, are identified. The engineering challenges associated with utilising metal hydrides for high-temperature TES are also addressed.}, note = {Online available at: \url{https://doi.org/10.1007/s00339-016-9825-0} (DOI). Sheppard, D.; Paskevicius, M.; Humphries, T.; Felderhoff, M.; Capurso, G.; Bellosta von Colbe, J.; Dornheim, M.; Klassem, T.; Ward, P.; Teprovich, J.; Corgnale, C.; Zidan, R.; Grant, D.; Buckley, C.: Metal hydrides for concentrating solar thermal power energy storage. Applied Physics A. 2016. vol. 122, no. 4, 395. DOI: 10.1007/s00339-016-9825-0}} @misc{capurso_development_of_2016, author={Capurso, G., Schiavo, B., Jepsen, J., Lozano, G., Metz, O., Saccone, A., de negri, S., Bellosta von Colbe, J.M., Klassen, T., Dornheim, M.}, title={Development of a modular room-temperature hydride storage system for vehicular applications}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s00339-016-9771-x}, abstract = {The subject of this paper concerns the development of a vehicular hydrogen tank system, using a commercial interstitial metal hydride as storage material. The design of the tank was intended to feed a fuel cell in a light prototype vehicle, and the chosen hydride material, Hydralloy C5 by GfE, was expected to be able to absorb and desorb hydrogen in a range of pressure suitable for this purpose. A systematic analysis of the material in laboratory scale allows an extrapolation of the thermodynamic and reaction kinetics data. The following development of the modular tank was done according to the requirements of the prototype vehicle propulsion system and led to promising intermediate results. The modular approach granted flexibility in the design, allowing both to reach carefully the design goals and to learn the limiting factors in the sorption process. Proper heat management and suitable equipment remain key factors in order to achieve the best performances.}, note = {Online available at: \url{https://doi.org/10.1007/s00339-016-9771-x} (DOI). Capurso, G.; Schiavo, B.; Jepsen, J.; Lozano, G.; Metz, O.; Saccone, A.; de negri, S.; Bellosta von Colbe, J.; Klassen, T.; Dornheim, M.: Development of a modular room-temperature hydride storage system for vehicular applications. Applied Physics A. 2016. vol. 122, no. 3, 236. DOI: 10.1007/s00339-016-9771-x}} @misc{callini_nanostructured_materials_2016, author={Callini, E., Aguey-Zinsou, K.-F., Ahuja, R., Ares, J.R., Bals, S., Biliskov, N., Chakraborty, S., Charalambopoulou, G., Chaudhary, A,-L., Cuevas, F., Dam, B., de Jongh, P., Dornheim, M., Filinchuk, Y., Grbovic Novakovic, J., Hirscher, M., Jensen, T.R., Jensen, P.B., Novakovic, N., Lai, Q., Leardini, F., Gattia, D.M., Pasquini, L., Steriotis, T., Turner, S., Vegge, T., Zuettel, A., Montone, A.}, title={Nanostructured materials for solid-state hydrogen storage: A review of the achievement of COST Action MP1103}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2016.04.025}, abstract = {In the framework of the European Cooperation in Science and Technology (COST) Action MP1103 Nanostructured Materials for Solid-State Hydrogen Storage were synthesized, characterized and modeled. This Action dealt with the state of the art of energy storage and set up a competitive and coordinated network capable to define new and unexplored ways for Solid State Hydrogen Storage by innovative and interdisciplinary research within the European Research Area. An important number of new compounds have been synthesized: metal hydrides, complex hydrides, metal halide ammines and amidoboranes. Tuning the structure from bulk to thin film, nanoparticles and nanoconfined composites improved the hydrogen sorption properties and opened the perspective to new technological applications. Direct imaging of the hydrogenation reactions and in situ measurements under operando conditions have been carried out in these studies. Computational screening methods allowed the prediction of suitable compounds for hydrogen storage and the modeling of the hydrogen sorption reactions on mono-, bi-, and three-dimensional systems. This manuscript presents a review of the main achievements of this Action.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2016.04.025} (DOI). Callini, E.; Aguey-Zinsou, K.; Ahuja, R.; Ares, J.; Bals, S.; Biliskov, N.; Chakraborty, S.; Charalambopoulou, G.; Chaudhary, A.; Cuevas, F.; Dam, B.; de Jongh, P.; Dornheim, M.; Filinchuk, Y.; Grbovic Novakovic, J.; Hirscher, M.; Jensen, T.; Jensen, P.; Novakovic, N.; Lai, Q.; Leardini, F.; Gattia, D.; Pasquini, L.; Steriotis, T.; Turner, S.; Vegge, T.; Zuettel, A.; Montone, A.: Nanostructured materials for solid-state hydrogen storage: A review of the achievement of COST Action MP1103. International Journal of Hydrogen Energy. 2016. vol. 41, no. 32, 14404-14428. DOI: 10.1016/j.ijhydene.2016.04.025}} @misc{wolff_magnesium_powder_2016, author={Wolff, M., Schaper, J., Suckert, M.-R., Dahms, M., Ebel, T., Willumeit-Roemer, R., Klassen, T.}, title={Magnesium Powder Injection Moulding (MIM) of Orthopedic Implants for Biomedical Applications}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s11837-016-1837-x}, abstract = {Metal injection molding (MIM) has a high potential for the economic near-net-shape mass production of small-sized and complex-shaped parts. The motivation for launching Mg into the MIM processing chain for manufacturing biodegradable medical implants is related to its compatibility with human bone and its degradation in a non-toxic matter. It has been recognized that the load-bearing capacity of MIM Mg parts is superior to that of biodegradable polymeric components. However, the choice of appropriate polymeric binder components and alloying elements enabling defect-free injection molding and sintering is a major challenge for the use of MIM Mg parts. This study considered the full processing chain for MIM of Mg–Ca alloys to achieve ultimate tensile strength of up to 141 MPa with tensile yield strength of 73 MPa, elongation at fracture Af of 7% and a Young’s modulus of 38 GPa. To achieve these mechanical properties, a thermal debinding study was performed to determine optimal furnace and atmosphere conditions, sintering temperature, heating rates, sintering time and pressure.}, note = {Online available at: \url{https://doi.org/10.1007/s11837-016-1837-x} (DOI). Wolff, M.; Schaper, J.; Suckert, M.; Dahms, M.; Ebel, T.; Willumeit-Roemer, R.; Klassen, T.: Magnesium Powder Injection Moulding (MIM) of Orthopedic Implants for Biomedical Applications. JOM: Journal of the Minerals, Metals and Materials Society. 2016. vol. 68, no. 4, 1191-1197. DOI: 10.1007/s11837-016-1837-x}} @misc{wolff_metal_injection_2016, author={Wolff, M., Schaper, J.G., Suckert, M.-R., Dahms, M., Feyerabend, F., Ebel, T., Willumeit-Roemer, R., Klassen, T.}, title={Metal Injection Molding (MIM) of Magnesium and Its Alloys}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.3390/met6050118}, abstract = {Current research has highlighted that magnesium and its alloys as biodegradable material are highly suitable for biomedical applications. The new material fully degrades into nontoxic elements and offers material properties matching those of human bone tissue. As biomedical implants are rather small and complex in shape, the metal injection molding (MIM) technique seems to be well suited for the near net shape mass production of such parts. Furthermore, MIM of Mg-alloys is of high interest in further technical fields. This study focusses on the performance of MIM-processing of magnesium alloy powders. It includes Mg-specific development of powder blending, feedstock preparation, injection molding, solvent and thermal debinding and final sintering. Even though Mg is a highly oxygen-affine material forming a stable oxide layer on each particle surface, the material can be sintered to nearly dense parts, providing mechanical properties matching those of as cast material. An ultimate tensile strength of 142 MPa, yield strength of 67 MPa, elastic modulus of 40 GPa and 8% elongation at fracture could be achieved using novel organic polymer binders for the feedstock preparation. Thus, first implant demonstrator parts could be successfully produced by the MIM technique.}, note = {Online available at: \url{https://doi.org/10.3390/met6050118} (DOI). Wolff, M.; Schaper, J.; Suckert, M.; Dahms, M.; Feyerabend, F.; Ebel, T.; Willumeit-Roemer, R.; Klassen, T.: Metal Injection Molding (MIM) of Magnesium and Its Alloys. Metals. 2016. vol. 6, no. 5, 118. DOI: 10.3390/met6050118}} @misc{nidadavolu_on_the_2016, author={Nidadavolu, E.P.S., Feyerabend, F., Ebel, T., Willumeit-Roemer, R., Dahms, M.}, title={On the Determination of Magnesium Degradation Rates under Physiological Conditions}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.3390/ma9080627}, abstract = {The current physiological in vitro tests of Mg degradation follow the procedure stated according to the ASTM standard. This standard, although useful in predicting the initial degradation behavior of an alloy, has its limitations in interpreting the same for longer periods of immersion in cell culture media. This is an important consequence as the alloy’s degradation is time dependent. Even if two different alloys show similar corrosion rates in a short term experiment, their degradation characteristics might differ with increased immersion times. Furthermore, studies concerning Mg corrosion extrapolate the corrosion rate from a single time point measurement to the order of a year (mm/y), which might not be appropriate because of time dependent degradation behavior. In this work, the above issues are addressed and a new methodology of performing long-term immersion tests in determining the degradation rates of Mg alloys was put forth. For this purpose, cast and extruded Mg-2Ag and powder pressed and sintered Mg-0.3Ca alloy systems were chosen. DMEM Glutamax +10% FBS (Fetal Bovine Serum) +1% Penicillin streptomycin was used as cell culture medium. The advantages of such a method in predicting the degradation rates in vivo deduced from in vitro experiments are discussed.}, note = {Online available at: \url{https://doi.org/10.3390/ma9080627} (DOI). Nidadavolu, E.; Feyerabend, F.; Ebel, T.; Willumeit-Roemer, R.; Dahms, M.: On the Determination of Magnesium Degradation Rates under Physiological Conditions. Materials. 2016. vol. 9, no. 8, 627. DOI: 10.3390/ma9080627}} @misc{hu_molecular_origin_2016, author={Hu, Y., Boudoire, F., Hermann-Geppert, I., Bogdanoff, P., Tsekouras, G., Mun, B.S., Fortunato, G., Graetzel, M., Braun, A.}, title={Molecular Origin and Electrochemical Influence of Capacitive Surface States on Iron Oxide Photoanodes}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.jpcc.5b08013}, abstract = {The origin, the nature, and the electronic structure of surface defects causing surface states on metal oxides and their role in solar water splitting have been under scrutiny for several decades. In the present study, the surface of hematite films is treated with an oxygen plasma and then subject to a detailed investigation with electroanalytical methods and element orbital specific X-ray spectroscopy. We observe a systemic variation of photoelectrochemical properties with oxygen treatment time. Fe 2p and O 1s core level X-ray photoelectron spectra and resonant valence band photoemission at the Fe 3p edge reveal the filling of prevalent oxygen vacancies with concomitant oxidation of Fe2+ to Fe3+ upon the oxygen treatment. The dc bias dependent impedance spectra confirm how a prevalent capacitive surface state, which evolves parallel with the photocurrent onset potential, becomes diminished upon oxygen treatment. Surface states of iron induce higher reactivity toward water oxidation than oxygen surface states. The correlation between oxygen vacancy filling, concentration of surface states, and photocurrent density in the course of treatment confirms that the surface defects are of a capacitive nature and that the onset of water splitting can be considered as a result of dielectric breakdown in an interfacial hydroxide layer between photoanode and water.}, note = {Online available at: \url{https://doi.org/10.1021/acs.jpcc.5b08013} (DOI). Hu, Y.; Boudoire, F.; Hermann-Geppert, I.; Bogdanoff, P.; Tsekouras, G.; Mun, B.; Fortunato, G.; Graetzel, M.; Braun, A.: Molecular Origin and Electrochemical Influence of Capacitive Surface States on Iron Oxide Photoanodes. The Journal of Physical Chemistry C. 2016. vol. 120, no. 6, 3250-3258. DOI: 10.1021/acs.jpcc.5b08013}} @misc{santoru_a_new_2016, author={Santoru, A., Garroni, S., Pistidda, C., Milanese, C., Girella, A., Marini, A., Masolo, E., Valentoni, A., Bergemann, N., Le, T.T., Cao, H., Haase, D., Balmes, O., Taube, K., Mulas, G., Enzo, S., Klassen, T., Dornheim, M.}, title={A new potassium-based intermediate and its role in the desorption properties of the K–Mg–N–H system}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1039/C5CP06963G}, abstract = {New insights into the reaction pathways of different potassium/magnesium amide–hydride based systems are discussed. In situ SR-PXD experiments were for the first time performed in order to reveal the evolution of the phases connected with the hydrogen releasing processes. Evidence of a new K–N–H intermediate is shown and discussed with particular focus on structural modification. Based on these results, a new reaction mechanism of amide–hydride anionic exchange is proposed.}, note = {Online available at: \url{https://doi.org/10.1039/C5CP06963G} (DOI). Santoru, A.; Garroni, S.; Pistidda, C.; Milanese, C.; Girella, A.; Marini, A.; Masolo, E.; Valentoni, A.; Bergemann, N.; Le, T.; Cao, H.; Haase, D.; Balmes, O.; Taube, K.; Mulas, G.; Enzo, S.; Klassen, T.; Dornheim, M.: A new potassium-based intermediate and its role in the desorption properties of the K–Mg–N–H system. Physical Chemistry Chemical Physics. 2016. vol. 18, no. 5, 3910-3920. DOI: 10.1039/C5CP06963G}} @misc{bergemann_cabh42mg2nih4_on_2016, author={Bergemann, N., Pistidda, C., Milanese, C., Emmler, T., Karimi, F., Chaudhary, A.-L., Chierotti, M.R., Klassen, T., Dornheim, M.}, title={Ca(BH4)2–Mg2NiH4: on the pathway to a Ca(BH4)2 system with a reversible hydrogen cycle}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c5cc09991a}, abstract = {The Ca(BH4)2–Mg2NiH4 system presented here is, to the best of our knowledge, the first described Ca(BH4)2-based hydride composite that reversibly transfers boron from the Ca-based compound(s) to the reaction partner. The ternary boride MgNi2.5B2 is formed upon dehydrogenation and the formation of Ca(BH4)2 upon rehydrogenation is confirmed.}, note = {Online available at: \url{https://doi.org/10.1039/c5cc09991a} (DOI). Bergemann, N.; Pistidda, C.; Milanese, C.; Emmler, T.; Karimi, F.; Chaudhary, A.; Chierotti, M.; Klassen, T.; Dornheim, M.: Ca(BH4)2–Mg2NiH4: on the pathway to a Ca(BH4)2 system with a reversible hydrogen cycle. Chemical Communications : ChemComm. 2016. vol. 52, no. 26, 4836-4839. DOI: 10.1039/c5cc09991a}} @misc{herrmanngeppert_cold_gas_2016, author={Herrmann-Geppert, I., Bogdanoff, P., Emmler, T., Dittrich, T., Radnik, J., Klassen, T., Gutzmann, H., Schieda, M.}, title={Cold gas spraying – A promising technique for photoelectrodes: The example TiO2}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.cattod.2015.06.007}, abstract = {For closer investigation of the influence of the process parameters on the photoelectrochemical activity, TiO2 electrodes (P25-20 by Evonik Industries) sprayed with different carrier gases (nitrogen, argon, helium) are analyzed. Due to different acceleration conditions of the particles in the de Laval nozzle, these carrier gases allow to investigate the influence of the impact energy of the particles on the binding mechanism and thus the resulting photocurrent density in the OER. Photoelectrochemical activities, structural properties as well as the electrode structure are correlated in order to discuss the history of the semiconductor and its photoelectrochemical properties evoked in the CGS process. Surface photovoltage measurements are considered to analyze the charge carrier dynamics in the porous TiO2 film. For the gas carrier nitrogen, beneficial conditions for the particle-to-particle and particle-to-substrate coupling are provided due to the sufficient temperature and velocity of the particles.}, note = {Online available at: \url{https://doi.org/10.1016/j.cattod.2015.06.007} (DOI). Herrmann-Geppert, I.; Bogdanoff, P.; Emmler, T.; Dittrich, T.; Radnik, J.; Klassen, T.; Gutzmann, H.; Schieda, M.: Cold gas spraying – A promising technique for photoelectrodes: The example TiO2. Catalysis Today. 2016. vol. 260, 140-147. DOI: 10.1016/j.cattod.2015.06.007}} @misc{santoru_knh2kh_a_2016, author={Santoru, A., Pistidda, C., Soerby, M.H., Chierotti, M.R., Garroni, S., Pinatel, E., Karimi, F., Cao, H., Bergemann, N., Le, T.T., Puszkiel, J., Gobetto, R., Baricco, M., Hauback, B.C., Klassen, T., Dornheim, M.}, title={KNH2–KH: a metal amide–hydride solid solution}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c6cc05777b}, abstract = {We report for the first time the formation of a metal amide–hydride solid solution. The dissolution of KH into KNH2 leads to an anionic substitution, which decreases the interaction among NH2− ions. The rotational properties of the high temperature polymorphs of KNH2 are thereby retained down to room temperature.}, note = {Online available at: \url{https://doi.org/10.1039/c6cc05777b} (DOI). Santoru, A.; Pistidda, C.; Soerby, M.; Chierotti, M.; Garroni, S.; Pinatel, E.; Karimi, F.; Cao, H.; Bergemann, N.; Le, T.; Puszkiel, J.; Gobetto, R.; Baricco, M.; Hauback, B.; Klassen, T.; Dornheim, M.: KNH2–KH: a metal amide–hydride solid solution. Chemical Communications : ChemComm. 2016. vol. 52, no. 79, 11760-11763. DOI: 10.1039/c6cc05777b}} @misc{cao_new_synthesis_2016, author={Cao, H., Santoru, A., Pistidda, C., Richter, T.M.M., Chaudhary, A.-L., Gizer, G., Niewa, R., Chen, P., Klassen, T., Dornheim, M.}, title={New synthesis route for ternary transition metal amides as well as ultrafast amide–hydride hydrogen storage materials}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1039/C6CC00719H}, abstract = {K2[Mn(NH2)4] and K2[Zn(NH2)4] were successfully synthesized via a mechanochemical method. The mixture of K2[Mn(NH2)4] and LiH showed excellent rehydrogenation properties. In fact, after dehydrogenation K2[Mn(NH2)4]-8LiH fully rehydrogenates within 60 seconds at ca. 230 °C and 5 MPa of H2. This is one of the fastest rehydrogenation rates in amide–hydride systems known to date. This work also shows a strategy for the synthesis of transition metal nitrides by decomposition of the mixtures of M[M′(NH2)n] (where M is an alkali or alkaline earth metal and M′ is a transition metal) and metal hydrides.}, note = {Online available at: \url{https://doi.org/10.1039/C6CC00719H} (DOI). Cao, H.; Santoru, A.; Pistidda, C.; Richter, T.; Chaudhary, A.; Gizer, G.; Niewa, R.; Chen, P.; Klassen, T.; Dornheim, M.: New synthesis route for ternary transition metal amides as well as ultrafast amide–hydride hydrogen storage materials. Chemical Communications : ChemComm. 2016. vol. 52, no. 29, 5100-5103. DOI: 10.1039/C6CC00719H}} @misc{wolff_metal_injection_2016, author={Wolff, M., Schaper, J., Suckert, M.R., Dahms, M., Feyerabend, F., Ebel, T., Willumeit-Roemer, R., Klassen, T.}, title={Metal Injection Molding (MIM) of Magnesium and Its Alloys}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.3390/met6050118}, abstract = {Current research has highlighted that magnesium and its alloys as biodegradable material are highly suitable for biomedical applications. The new material fully degrades into nontoxic elements and offers material properties matching those of human bone tissue. As biomedical implants are rather small and complex in shape, the metal injection molding (MIM) technique seems to be well suited for the near net shape mass production of such parts. Furthermore, MIM of Mg-alloys is of high interest in further technical fields. This study focusses on the performance of MIM-processing of magnesium alloy powders. It includes Mg-specific development of powder blending, feedstock preparation, injection molding, solvent and thermal debinding and final sintering. Even though Mg is a highly oxygen-affine material forming a stable oxide layer on each particle surface, the material can be sintered to nearly dense parts, providing mechanical properties matching those of as cast material. An ultimate tensile strength of 142 MPa, yield strength of 67 MPa, elastic modulus of 40 GPa and 8% elongation at fracture could be achieved using novel organic polymer binders for the feedstock preparation. Thus, first implant demonstrator parts could be successfully produced by the MIM technique.}, note = {Online available at: \url{https://doi.org/10.3390/met6050118} (DOI). Wolff, M.; Schaper, J.; Suckert, M.; Dahms, M.; Feyerabend, F.; Ebel, T.; Willumeit-Roemer, R.; Klassen, T.: Metal Injection Molding (MIM) of Magnesium and Its Alloys. Metals. 2016. vol. 6, no. 5, 118. DOI: 10.3390/met6050118}} @misc{crivello_review_of_2016, author={Crivello, J.-C., Dam, B., Denys, R.V., Dornheim, M., Grant, D.M., Huot, J., jensen, T.R., de jongh, P., Latroche, M., Milanese, C., Milcius, D., Walker, G.S., Webb, C.J., Zlotea, C., Yartys, V.A.}, title={Review of magnesium hydride-based materials: development and optimisation}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s00339-016-9602-0}, abstract = {Magnesium hydride has been studied extensively for applications as a hydrogen storage material owing to the favourable cost and high gravimetric and volumetric hydrogen densities. However, its high enthalpy of decomposition necessitates high working temperatures for hydrogen desorption while the slow rates for some processes such as hydrogen diffusion through the bulk create challenges for large-scale implementation. The present paper reviews fundamentals of the Mg–H system and looks at the recent advances in the optimisation of magnesium hydride as a hydrogen storage material through the use of catalytic additives, incorporation of defects and an understanding of the rate-limiting processes during absorption and desorption.}, note = {Online available at: \url{https://doi.org/10.1007/s00339-016-9602-0} (DOI). Crivello, J.; Dam, B.; Denys, R.; Dornheim, M.; Grant, D.; Huot, J.; jensen, T.; de jongh, P.; Latroche, M.; Milanese, C.; Milcius, D.; Walker, G.; Webb, C.; Zlotea, C.; Yartys, V.: Review of magnesium hydride-based materials: development and optimisation. Applied Physics A. 2016. vol. 122, no. 2, 97. DOI: 10.1007/s00339-016-9602-0}} @misc{stoermer_preparation_and_2016, author={Stoermer, M., Siewert, F., Sinn, H.}, title={Preparation and characterization of B4C coatings for advanced research light sources}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S1600577515020901}, abstract = {X-ray optical elements are required for beam transport at the current and upcoming free-electron lasers and synchrotron sources. An X-ray mirror is a combination of a substrate and a coating. The demand for large mirrors with single layers consisting of light or heavy elements has increased during the last few decades; surface finishing technology is currently able to process mirror lengths up to 1 m with microroughness at the sub-nanometre level. Additionally, thin-film fabrication is able to deposit a suitable single-layer material, such as boron carbide (B4C), some tens of nanometres thick. After deposition, the mirror should provide excellent X-ray optical properties with respect to coating thickness errors, microroughness values and slope errors; thereby enabling the mirror to transport the X-ray beam with high reflectivity, high beam flux and an undistorted wavefront to an experimental station. At the European XFEL, the technical specifications of the future mirrors are extraordinarily challenging. The acceptable shape error of the mirrors is below 2 nm along the whole length of 1 m. At the Helmholtz-Zentrum Geesthacht (HZG), amorphous layers of boron carbide with thicknesses in the range 30-60 nm were fabricated using the HZG sputtering facility, which is able to cover areas up to 1500 mm long by 120 mm wide in one step using rectangular B4C sputtering targets. The available deposition area is suitable for the specified X-ray mirror dimensions of upcoming advanced research light sources such as the European XFEL. The coatings produced were investigated by means of X-ray reflectometry and interference microscopy. The experimental results for the B4C layers are discussed according to thickness uniformity, density, microroughness and thermal stability. The variation of layer thickness in the tangential and sagittal directions was investigated in order to estimate the achieved level of uniformity over the whole deposition area, which is considerably larger than the optical area of a mirror. A waisted mask was positioned during deposition between the sputtering source and substrate to improve the thickness uniformity; particularly to prevent the formation a convex film shape in the sagittal direction. Additionally the inclination of the substrate was varied to change the layer uniformity in order to optimize the position of the mirror quality deposited area during deposition. The level of mirror microroughness was investigated for different substrates before and after deposition of a single layer of B4C. The thermal stability of the B4C layers on the various substrate materials was investigated.}, note = {Online available at: \url{https://doi.org/10.1107/S1600577515020901} (DOI). Stoermer, M.; Siewert, F.; Sinn, H.: Preparation and characterization of B4C coatings for advanced research light sources. Journal of Synchrotron Radiation. 2016. vol. 23, 50-58. DOI: 10.1107/S1600577515020901}} @misc{utke_2libh4mgh2_nanoconfined_2016, author={Utke, R., Thiangviriya, S., Javadian, P., jensen, T.R., Milanese, C., Klassen, T., Dornheim, M.}, title={2LiBH4–MgH2 nanoconfined into carbon aerogel scaffold impregnated with ZrCl4 for reversible hydrogen storage}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.matchemphys.2015.11.040}, abstract = {Nanoconfinement of 2LiBH4–MgH2 composite into carbon aerogel scaffold (CAS) impregnated with zirconium (IV) chloride (ZrCl4) for reversible hydrogen storage is proposed. Nanoconfined samples prepared with hydride:ZrCl4-doped CAS weight ratios of 1:1, 1:2, and 1:3 are prepared by melt infiltration technique. Successful nanoconfinement of all samples is confirmed and it is found that the sample with high content of hydride with respect to ZrCl4-doped CAS (1:1 weight ratio) shows partial pore blocking. The most suitable hydride:ZrCl4-doped CAS weight ratio providing the best performance based on dehydrogenation temperature and kinetics as well as hydrogen storage capacity is 1:2. Reduction of dehydrogenation temperature and faster kinetics are obtained after doping with ZrCl4. Up to 97 and 93% of theoretical hydrogen storage capacity are released and reproduced after four cycles of nanoconfined sample with ZrCl4 (1:2 weight ratio). Deficient hydrogen content with respect to theoretical capacity can be due to partial dehydrogenation during melt infiltration and formation of thermally stable [B12H12]2- phases during cycling.}, note = {Online available at: \url{https://doi.org/10.1016/j.matchemphys.2015.11.040} (DOI). Utke, R.; Thiangviriya, S.; Javadian, P.; jensen, T.; Milanese, C.; Klassen, T.; Dornheim, M.: 2LiBH4–MgH2 nanoconfined into carbon aerogel scaffold impregnated with ZrCl4 for reversible hydrogen storage. Materials Chemistry and Physics. 2016. vol. 169, 136-141. DOI: 10.1016/j.matchemphys.2015.11.040}} @misc{callini_complex_and_2016, author={Callini, E., Atakli, Z.Oe.K., Hauback, B.C., Orimo, S.-I., Jensen, C., Dornheim, M., Grant, D., Cho, Y.W., Chen, P., Hjoervarsson, B., de Jongh, P., Weidenthaler, C., Baricco, M., Paskevicius, M., Jensen, T.R., bowden, M.E., Autrey, T.S., Zuettel, A.}, title={Complex and liquid hydrides for energy storage}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s00339-016-9881-5}, abstract = {The research on complex hydrides for hydrogen storage was initiated by the discovery of Ti as a hydrogen sorption catalyst in NaAlH4 by Boris Bogdanovic in 1996. A large number of new complex hydride materials in various forms and combinations have been synthesized and characterized, and the knowledge regarding the properties of complex hydrides and the synthesis methods has grown enormously since then. A significant portion of the research groups active in the field of complex hydrides is collaborators in the International Energy Agreement Task 32. This paper reports about the important issues in the field of complex hydride research, i.e. the synthesis of borohydrides, the thermodynamics of complex hydrides, the effects of size and confinement, the hydrogen sorption mechanism and the complex hydride composites as well as the properties of liquid complex hydrides. This paper is the result of the collaboration of several groups and is an excellent summary of the recent achievements.}, note = {Online available at: \url{https://doi.org/10.1007/s00339-016-9881-5} (DOI). Callini, E.; Atakli, Z.; Hauback, B.; Orimo, S.; Jensen, C.; Dornheim, M.; Grant, D.; Cho, Y.; Chen, P.; Hjoervarsson, B.; de Jongh, P.; Weidenthaler, C.; Baricco, M.; Paskevicius, M.; Jensen, T.; bowden, M.; Autrey, T.; Zuettel, A.: Complex and liquid hydrides for energy storage. Applied Physics A. 2016. vol. 122, no. 4, 353. DOI: 10.1007/s00339-016-9881-5}} @misc{boerries_optimization_and_2016, author={Boerries, S., Metz, O., Pranzas, P.K., Bellosta von Colbe, J.M., Buecherl, T., Dornheim, M., Schreyer, A.}, title={Optimization and comprehensive characterization of metal hydride based hydrogen storage systems using in-situ Neutron Radiography}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jpowsour.2016.08.040}, abstract = {For the storage of hydrogen, complex metal hydrides are considered as highly promising with respect to capacity, reversibility and safety. The optimization of corresponding storage tanks demands a precise and time-resolved investigation of the hydrogen distribution in scaled-up metal hydride beds. In this study it is shown that in situ fission Neutron Radiography provides unique insights into the spatial distribution of hydrogen even for scaled-up compacts and therewith enables a direct study of hydrogen storage tanks. A technique is introduced for the precise quantification of both time-resolved data and a priori material distribution, allowing inter alia for an optimization of compacts manufacturing process. For the first time, several macroscopic fields are combined which elucidates the great potential of Neutron Imaging for investigations of metal hydrides by going further than solely ’imaging’ the system: A combination of in-situ Neutron Radiography, IR-Thermography and thermodynamic quantities can reveal the interdependency of different driving forces for a scaled-up sodium alanate pellet by means of a multi-correlation analysis. A decisive and time-resolved, complex influence of material packing density is derived. The results of this study enable a variety of new investigation possibilities that provide essential information on the optimization of future hydrogen storage tanks.}, note = {Online available at: \url{https://doi.org/10.1016/j.jpowsour.2016.08.040} (DOI). Boerries, S.; Metz, O.; Pranzas, P.; Bellosta von Colbe, J.; Buecherl, T.; Dornheim, M.; Schreyer, A.: Optimization and comprehensive characterization of metal hydride based hydrogen storage systems using in-situ Neutron Radiography. Journal of Power Sources. 2016. vol. 328, 567-577. DOI: 10.1016/j.jpowsour.2016.08.040}} @misc{stoermer_ultraprecision_fabrication_2016, author={Stoermer, M., Gabrisch, H., Horstmann, C., Heidorn, U., Hertlein, F., Wiesmann, J., Siewert, F., Rack, A.}, title={Ultra-precision fabrication of 500 mm long and laterally graded Ru/C multilayer mirrors for X-ray light sources}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1063/1.4950748}, abstract = {X-ray mirrors are needed for beam shaping and monochromatization at advanced research light sources, for instance, free-electron lasers and synchrotron sources. Such mirrors consist of a substrate and a coating. The shape accuracy of the substrate and the layer precision of the coating are the crucial parameters that determine the beam properties required for various applications. In principal, the selection of the layer materials determines the mirror reflectivity. A single layer mirror offers high reflectivity in the range of total external reflection, whereas the reflectivity is reduced considerably above the critical angle. A periodic multilayer can enhance the reflectivity at higher angles due to Bragg reflection. Here, the selection of a suitable combination of layer materials is essential to achieve a high flux at distinct photon energies, which is often required for applications such as microtomography, diffraction, or protein crystallography. This contribution presents the current development of a Ru/C multilayer mirror prepared by magnetron sputtering with a sputtering facility that was designed in-house at the Helmholtz-Zentrum Geesthacht. The deposition conditions were optimized in order to achieve ultra-high precision and high flux in future mirrors. Input for the improved deposition parameters came from investigations by transmission electron microscopy. The X-ray optical properties were investigated by means of X-ray reflectometry using Cu- and Mo-radiation. The change of the multilayer d-spacing over the mirror dimensions and the variation of the Bragg angles were determined. The results demonstrate the ability to precisely control the variation in thickness over the whole mirror length of 500 mm thus achieving picometer-precision in the meter-range.}, note = {Online available at: \url{https://doi.org/10.1063/1.4950748} (DOI). Stoermer, M.; Gabrisch, H.; Horstmann, C.; Heidorn, U.; Hertlein, F.; Wiesmann, J.; Siewert, F.; Rack, A.: Ultra-precision fabrication of 500 mm long and laterally graded Ru/C multilayer mirrors for X-ray light sources. Review of Scientific Instruments. 2016. vol. 87, no. 5, 051804. DOI: 10.1063/1.4950748}} @misc{dyachenko_controlling_thermal_2016, author={Dyachenko, P.N., Molesky, S., Petrov, A.Y., Stoermer, M., Krekeler, T., Lang, S., Ritter, M., Jacob, Z., Eich, M.}, title={Controlling thermal emission with refractory epsilon-near-zero metamaterials via topological transitions}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1038/ncomms11809}, abstract = {Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C.}, note = {Online available at: \url{https://doi.org/10.1038/ncomms11809} (DOI). Dyachenko, P.; Molesky, S.; Petrov, A.; Stoermer, M.; Krekeler, T.; Lang, S.; Ritter, M.; Jacob, Z.; Eich, M.: Controlling thermal emission with refractory epsilon-near-zero metamaterials via topological transitions. Nature Communications. 2016. vol. 7, 11809. DOI: 10.1038/ncomms11809}} @misc{paskevicius_cyclic_stability_2016, author={Paskevicius, M., Filsoe, U., Karimi, F., Puszkiel, J., Pranzas, P.K., Pistidda, C., Hoell, A., Welter, E., Schreyer, A., Klassen, T., Dornheim, M., Jensen, T.R.}, title={Cyclic stability and structure of nanoconfined Ti-doped NaAlH4}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2015.12.185}, abstract = {NaAlH4 was melt infiltrated within a CO2 activated carbon aerogel, which had been preloaded with TiCl3. Nanoconfinement was verified by Small Angle X-Ray Scattering (SAXS) and the nature of the Ti was investigated with Anomalous SAXS (ASAXS) and X-Ray Absorption Near Edge Structure (XANES) to determine its size and chemical state. The Ti is found to be in a similar state to that found in the bulk Ti-doped NaAlH4 system where it exists as Al1−xTix nanoalloys. Crystalline phases exist within the carbon aerogel pores, which are analysed by in-situ Powder X-Ray Diffraction (PXD) during hydrogen cycling. The in-situ data reveals that the hydrogen release from NaAlH4 and its hydrogen uptake occurs through the Na3AlH6 intermediate when confined at this size scale. The hydrogen capacity from the nanoconfined NaAlH4 is found to initially be much higher in this CO2 activated aerogel compared with previous studies into unactivated aerogels.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2015.12.185} (DOI). Paskevicius, M.; Filsoe, U.; Karimi, F.; Puszkiel, J.; Pranzas, P.; Pistidda, C.; Hoell, A.; Welter, E.; Schreyer, A.; Klassen, T.; Dornheim, M.; Jensen, T.: Cyclic stability and structure of nanoconfined Ti-doped NaAlH4. International Journal of Hydrogen Energy. 2016. vol. 41, no. 7, 4159-4167. DOI: 10.1016/j.ijhydene.2015.12.185}} @misc{kozhevnikov_growth_of_2016, author={Kozhevnikov, I.V., Buzmakov, A.V., Siewert, F., Tiedtke, K., Stoermer, M., Samoylova, L., Sinn, H.}, title={Growth of nano-dots on the grazing-incidence mirror surface under FEL irradiation}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S160057751502202X}, abstract = {A new phenomenon on X-ray optics surfaces has been observed: the growth of nano-dots (40-55 nm diameter, 8-13 nm height, 9.4 dots µm-2 surface density) on the grazing-incidence mirror surface under irradiation by the free-electron laser (FEL) FLASH (5-45 nm wavelength, 3° grazing-incidence angle). With a model calculation it is shown that these nano-dots may occur during the growth of a contamination layer due to polymerization of incoming hydrocarbon molecules. The crucial factors responsible for the growth of nano-dots in the model are the incident peak intensity and the reflection angle of the beam. A reduction of the peak intensity (e.g. replacement of the FEL beam by synchrotron radiation) as well as a decrease of the incident angle by just 1° (from 3° to 2°) may result in the total disappearance of the nano-dots. The model calculations are compared with surface analysis of two FLASH mirrors.}, note = {Online available at: \url{https://doi.org/10.1107/S160057751502202X} (DOI). Kozhevnikov, I.; Buzmakov, A.; Siewert, F.; Tiedtke, K.; Stoermer, M.; Samoylova, L.; Sinn, H.: Growth of nano-dots on the grazing-incidence mirror surface under FEL irradiation. Journal of Synchrotron Radiation. 2016. vol. 23, no. 1, 78-90. DOI: 10.1107/S160057751502202X}} @misc{heere_milling_time_2016, author={Heere, M., Soerby, M.H., Pistidda, C., Dornheim, M., Hauback, B.C.}, title={Milling time effect of Reactive Hydride Composites of NaF-NaH-MgB2 investigated by in situ powder diffraction}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2016.05.153}, abstract = {Light metal complex borohydrides have high hydrogen storage capacities but suffer from drawbacks of slow hydrogen sorption kinetics, poor reversibility and high thermodynamic stability. The NaF + 9NaH + 5MgB2 composite has a theoretical hydrogen capacity of 7.7 wt% H assuming the formation of 10NaBH3.9F0.1 + 5MgH2. Hydrogenation and dehydrogenation properties as well as the effect of different ball milling times have been investigated. The in situ hydrogenation is faster in the composite ball milled for 87 h than the 5 h milled composite. A boron-rich phase with space group Pa-3, a = 7.4124(5) Å was formed during hydrogenation at 325 °C and 50 bar hydrogen for both short and long milling times. In the long milled composite the boron-rich phase disappeared after 3 h of hydrogenation, whereas it became a major phase in the short milled composite after 1.5 h of hydrogenation. NaBH4 was formed at 206 °C. NaMgH1-xFx was formed at 290 °C instead of the assumed MgH2. The same phases formed at 268 °C and 325 °C, respectively, and only in minor amounts in the short milled composite. Ex situ hydrogenation in a Sieverts' type apparatus at the same temperature and hydrogen pressure conditions followed a different reaction pathway with formation of MgH2 in addition to NaBH4 and NaMgH3-xFx (0 ≤ x ≤ 1). The measured hydrogen uptake was 6.0 and 6.3 wt% for the long and short milled composites, respectively.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2016.05.153} (DOI). Heere, M.; Soerby, M.; Pistidda, C.; Dornheim, M.; Hauback, B.: Milling time effect of Reactive Hydride Composites of NaF-NaH-MgB2 investigated by in situ powder diffraction. International Journal of Hydrogen Energy. 2016. vol. 41, no. 30, 13101-13108. DOI: 10.1016/j.ijhydene.2016.05.153}} @misc{crivello_mgbased_compounds_2016, author={Crivello, J.-C., Denys, R.V., Dornheim, M., Felderhoff, M., Grant, D.M., Huot, J., Jensen, T.R., de Jongh, P., Latroche, M., Walker, G.S., Webb, C.J., Yartys, V.A.}, title={Mg-based compounds for hydrogen and energy storage}, year={2016}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s00339-016-9601-1}, abstract = {Magnesium-based alloys attract significant interest as cost-efficient hydrogen storage materials allowing the combination of high gravimetric storage capacity of hydrogen with fast rates of hydrogen uptake and release and pronounced destabilization of the metal–hydrogen bonding in comparison with binary Mg–H systems. In this review, various groups of magnesium compounds are considered, including (1) RE–Mg–Ni hydrides (RE = La, Pr, Nd); (2) Mg alloys with p-elements (X = Si, Ge, Sn, and Al); and (3) magnesium alloys with d-elements (Ti, Fe, Co, Ni, Cu, Zn, Pd). The hydrogenation–disproportionation–desorption–recombination process in the Mg-based alloys (LaMg12, LaMg11Ni) and unusually high-pressure hydrides synthesized at pressures exceeding 100 MPa (MgNi2H3) and stabilized by Ni–H bonding are also discussed. The paper reviews interrelations between the properties of the Mg-based hydrides and p–T conditions of the metal–hydrogen interactions, chemical composition of the initial alloys, their crystal structures, and microstructural state.}, note = {Online available at: \url{https://doi.org/10.1007/s00339-016-9601-1} (DOI). Crivello, J.; Denys, R.; Dornheim, M.; Felderhoff, M.; Grant, D.; Huot, J.; Jensen, T.; de Jongh, P.; Latroche, M.; Walker, G.; Webb, C.; Yartys, V.: Mg-based compounds for hydrogen and energy storage. Applied Physics A. 2016. vol. 122, 85. DOI: 10.1007/s00339-016-9601-1}} @misc{busch_influence_of_2015, author={Busch, N., Jepsen, J., Pistidda, C., Puszkiel, J.A., Karimi, F., Milanese, C., Tolkiehn, M., Chaudhary, A.-L., Klassen, T., Dornheim, M.}, title={Influence of milling parameters on the sorption properties of the LiH-MgB2 system doped with TiCl3}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2014.12.187}, abstract = {Hydrogen sorption properties of the LiH–MgB2 system doped with TiCl3 were investigated with respect to milling conditions (milling times, ball to powder (BTP) ratios, rotation velocities and degrees of filling) to form the reactive hydride composite (RHC) LiBH4–MgH2. A heuristic model was applied to approximate the energy transfer from the mill to the powders. These results were linked to experimentally obtained quantities such as crystallite size, specific surface area (SSA) and homogeneity of the samples, using X-ray diffraction (XRD), the Brunauer–Emmett–Teller (BET) method and scanning electron microscopy (SEM), respectively. The results show that at approximately 20 kJ g−1 there are no further benefits to the system with an increase in energy transfer. This optimum energy transfer value indicates that a plateau was reached for MgB2 crystallite size therefore the there was also no improvement of reaction kinetics due to no change in crystallite size. Therefore, this study shows that an optimum energy transfer value was reached for the LiH–MgB2 system doped with TiCl3.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2014.12.187} (DOI). Busch, N.; Jepsen, J.; Pistidda, C.; Puszkiel, J.; Karimi, F.; Milanese, C.; Tolkiehn, M.; Chaudhary, A.; Klassen, T.; Dornheim, M.: Influence of milling parameters on the sorption properties of the LiH-MgB2 system doped with TiCl3. Journal of Alloys and Compounds. 2015. vol. 645, no. S 1, S299-S303. DOI: 10.1016/j.jallcom.2014.12.187}} @misc{wolff_untersuchung_des_2015, author={Wolff, M., Schaper, J., Rüder, N., Vogt, C., Feyerabend, F., Dahms, M., Willumeit-Römer, R., Ebel, T., Klassen, T.}, title={Untersuchung des Einflusses von Verunreinigungen auf das Bioabbauverhalten metallischer Mg-Ca basierter Implantate}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1515/bnm-2015-9007}, abstract = {In jüngster Zeit findet Mg zunehmendes Interesse als bioabbaubares Implantatmaterial für zukünftige biomedizinische Anwendungen [1, 2]. Zur Konditionierung von Festigkeit, Steifigkeit und Degradationsverhalten werden derzeit Legierungselemente (LE) wie z.B. Gd/Dy/Zn/Ag oder Ca untersucht. Neben dem Einfluss dieser LE auf das Bioabbauverhalten darf jedoch der Einfluss von bereits im Ausgangsmaterial vorhandenen Verunreinigungen wie Fe, Ni oder Cu nicht außer Acht gelassen werden. Dieser spielt bei der Eignungsfeststellung der gewählten Mg-Legierung als Biomaterial möglicherweise eine Schlüsselrolle und kann die eigentliche Wirkung des gewählten LE überdecken. Dies wiederum kann zur Fehlinterpretation von Ergebnissen und zur falschen Schlussfindung bei der Legierungswahl führen. Um dies zu verhindern ist ein vollständiger Wissensschatz über die vorhandenen Verunreinigungen und dessen Einfluss auf das Bioabbauverhalten notwendig. Diese Arbeit gibt einen Überblick wie Verunreinigungen an homogenem pulvermetallurgischen (PM) Ausgangsmaterialien bestimmt werden können und wie sie die Bioabbaubarkeit beeinflussen.}, note = {Online available at: \url{https://doi.org/10.1515/bnm-2015-9007} (DOI). Wolff, M.; Schaper, J.; Rüder, N.; Vogt, C.; Feyerabend, F.; Dahms, M.; Willumeit-Römer, R.; Ebel, T.; Klassen, T.: Untersuchung des Einflusses von Verunreinigungen auf das Bioabbauverhalten metallischer Mg-Ca basierter Implantate. BioNanoMaterials. 2015. vol. 16, no. 2-3, 114-121. DOI: 10.1515/bnm-2015-9007}} @misc{dorchies_time_evolution_2015, author={Dorchies, F., Recoules, V., Bouchet, J., Fourment, C., Leguay, P.M., Cho, B.I., Engelhorn, K., Nakatsutsumi, M., Ozkan, C., Tschentscher, T., Harmand, M., Toleikis, S., Stoermer, M., Galtier, E., Lee, H.J., Nagler, B., Heimann, P.A., Gaudin, J.}, title={Time evolution of electron structure in femtosecond heated warm dense molybdenum}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1103/PhysRevB.92.144201}, abstract = {The time evolution of the electron structure is investigated in a molybdenum foil heated up to the warm dense matter regime by a femtosecond laser pulse, through time-resolved x-ray absorption near-edge spectroscopy. Spectra are measured with independent characterizations of temperature and density. They are successfully compared with ab initio quantum molecular dynamic calculations. We demonstrate that the observed white line in the L3 edge reveals the time evolution of the electron density of state from the solid to the hot (a few eV) and expanding liquid. The data indicate a highly nonequilibrated state, 5 ps after heating.}, note = {Online available at: \url{https://doi.org/10.1103/PhysRevB.92.144201} (DOI). Dorchies, F.; Recoules, V.; Bouchet, J.; Fourment, C.; Leguay, P.; Cho, B.; Engelhorn, K.; Nakatsutsumi, M.; Ozkan, C.; Tschentscher, T.; Harmand, M.; Toleikis, S.; Stoermer, M.; Galtier, E.; Lee, H.; Nagler, B.; Heimann, P.; Gaudin, J.: Time evolution of electron structure in femtosecond heated warm dense molybdenum. Physical Review B. 2015. vol. 92, no. 14, 144201. DOI: 10.1103/PhysRevB.92.144201}} @misc{pistidda_first_direct_2015, author={Pistidda, C., Santoru, A., Garroni, S., Bergemann, N., Rzeszutek, A., Horstmann, C., Thomas, D., Klassen, T., Dornheim, M.}, title={First Direct Study of the Ammonolysis Reaction in the Most Common Alkaline and Alkaline Earth Metal Hydrides by in Situ SR-PXD}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp510720x}, abstract = {We report on the first in situ synchrotron radiation powder X-ray diffraction study (SR-PXD) of the ammonolysis reaction of selected alkaline and alkaline earth metal hydrides (i.e., LiH, NaH, KH, MgH2, and CaH2). The investigation was performed using an in situ SR-PXD pressure cell at an initial NH3 pressure of 6.5 bar in a range of temperature between room temperature (RT) and 350 °C. The results of this work give new important insights into the formation of metal amides and imides starting from the corresponding metal hydrides. LiH was observed to react with NH3 to form LiNH2 already at RT, and then it decomposes into Li2NH at 310 °C through the formation of nonstoichiometric intermediates of the Li1+xNH2–x form. The formation of NaNH2 takes place nearly at RT (28 °C), and it melts at 180 °C. As for LiH, KH reacts with NH3 at RT to surprisingly form, what it seems to be, cubic KNH2. However, we believe this phase to be a solid solution of KH in KNH2. At high temperature, the possible formation of several solid solutions of K(NH2)1–yHy with defined composition is also observed. The formation of Mg(NH2)2 was observed to starts at around 220 °C, from the interaction γ-MgH2 and NH3. At 350 °C, when all γ-MgH2 is consumed, the formation of Mg(NH2)2 stops and MgNH is formed by the reaction between β-MgH2 and NH3. Our results indicate that the formation of the γ-MgH2 is a key step in the synthesis of Mg(NH2)2 at low temperature (e.g., via ball milling technique). CaH2 was observed to react with NH3 at around 140 °C to form CaNH. At higher temperature the appearance of new reflections of possible Ca1+xNH phases, with the same crystalline structure of CaNH but with a smaller cell parameter was observed.}, note = {Online available at: \url{https://doi.org/10.1021/jp510720x} (DOI). Pistidda, C.; Santoru, A.; Garroni, S.; Bergemann, N.; Rzeszutek, A.; Horstmann, C.; Thomas, D.; Klassen, T.; Dornheim, M.: First Direct Study of the Ammonolysis Reaction in the Most Common Alkaline and Alkaline Earth Metal Hydrides by in Situ SR-PXD. The Journal of Physical Chemistry C. 2015. vol. 119, no. 2, 934-943. DOI: 10.1021/jp510720x}} @misc{bonattominella_sorption_properties_2015, author={Bonatto Minella, C., Garroni, S., Pistidda, C., Baro, M.D., Gutfleisch, O., Klassen, T., Dornheim, M.}, title={Sorption properties and reversibility of Ti(IV) and Nb(V)-fluoride doped-Ca(BH4)2–MgH2 system}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2014.11.038}, abstract = {The addition of NbF5 or TiF4 to the Ca(BH4)2 + MgH2 system have not suppressed completely the formation of CaB12H12 and only a slight improvement concerning the reversible reaction was displayed just in the case of Nb-doped composite material.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2014.11.038} (DOI). Bonatto Minella, C.; Garroni, S.; Pistidda, C.; Baro, M.; Gutfleisch, O.; Klassen, T.; Dornheim, M.: Sorption properties and reversibility of Ti(IV) and Nb(V)-fluoride doped-Ca(BH4)2–MgH2 system. Journal of Alloys and Compounds. 2015. vol. 622, 989-994. DOI: 10.1016/j.jallcom.2014.11.038}} @misc{suarezalcantara_synchrotron_diffraction_2015, author={Suarez-Alcantara, K., Soerby, M.H., Pistidda, C., Karimi, F., Saldan, I., Hauback, B.C., Klassen, T., Dornheim, M.}, title={Synchrotron Diffraction Studies of Hydrogen Absorption/Desorption on CaH2 + MgB2 Reactive Hydride Composite Mixed With Fluorinated Compounds}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.jpcc.5b01961}, abstract = {The reactive hydride composites 9CaH2 + CaF2 + 10MgB2, 10Ca(BH4)2 + 9MgH2 + MgF2, and 9Ca(BH4)2 + Ca(BF4)2 + 10MgH2 were prepared by ball milling. Their properties toward hydrogen absorption/desorption were tested by means of manometric measurements. The highest hydrogen storage capacity was obtained for 9CaH2 + CaF2 + 10MgB2 (7.6 wt %) at the first cycle. The effects of CaF2, MgF2, or Ca(BF4)2 on the dehydrogenation reaction were studied by means of in situ synchrotron radiation powder X-ray diffraction (in situ SR-PXD) and differential scanning calorimetry (DSC). The high resolution SR-PXD technique was used to confirm the formation of hydrogenated products and side products in the 9CaH2 + CaF2 + 10MgB2 reactive hydride composites. These studies indicate the formation of a complex mixture of phases.}, note = {Online available at: \url{https://doi.org/10.1021/acs.jpcc.5b01961} (DOI). Suarez-Alcantara, K.; Soerby, M.; Pistidda, C.; Karimi, F.; Saldan, I.; Hauback, B.; Klassen, T.; Dornheim, M.: Synchrotron Diffraction Studies of Hydrogen Absorption/Desorption on CaH2 + MgB2 Reactive Hydride Composite Mixed With Fluorinated Compounds. The Journal of Physical Chemistry C. 2015. vol. 119, no. 21, 11430-11437. DOI: 10.1021/acs.jpcc.5b01961}} @misc{chaudhary_simultaneous_desorption_2015, author={Chaudhary, A.-L., Li, G., Matsuo, M., Orimo, S., Deledda, S., Soerby, M.H., Hauback, B.C., Pistidda, C., Klassen, T., Dornheim, M.}, title={Simultaneous desorption behavior of M borohydrides and Mg2FeH6 reactive hydride composites (M = Mg, then Li, Na, K, Ca)}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1063/1.4929340}, abstract = {Combinations of complex metal borohydrides ball milled with the transition metal complex hydride, Mg2FeH6, are analysed and compared. Initially, the Reactive Hydride Composite (RHC) of Mg2+ cation mixtures of Mg2FeH6 and γ-Mg(BH4)2 is combined in a range of molar ratios and heated to a maximum of 450 °C. For the molar ratio of 6 Mg2FeH6 + Mg(BH4)2, simultaneous desorption of the two hydrides occurred, which resulted in a single event of hydrogen release. This single step desorption occurred at temperatures between those of Mg2FeH6 and γ-Mg(BH4)2. Keeping this anionic ratio constant, the desorption behavior of four other borohydrides, Li-, Na-, K-, and Ca-borohydrides was studied by using materials ball milled with Mg2FeH6 applying the same milling parameters. The mixtures containing Mg-, Li-, and Ca-borohydrides also released hydrogen in a single event. The Mass Spectrometry (MS) results show a double step reaction within a narrow temperature range for both the Na- and K-borohydride mixtures. This phenomenon, observed for the RHC systems at the same anionic ratio with all five light metal borohydride mixtures, can be described as simultaneous hydrogen desorption within a narrow temperature range centered around 300 °C.}, note = {Online available at: \url{https://doi.org/10.1063/1.4929340} (DOI). Chaudhary, A.; Li, G.; Matsuo, M.; Orimo, S.; Deledda, S.; Soerby, M.; Hauback, B.; Pistidda, C.; Klassen, T.; Dornheim, M.: Simultaneous desorption behavior of M borohydrides and Mg2FeH6 reactive hydride composites (M = Mg, then Li, Na, K, Ca). Applied Physics Letters. 2015. vol. 107, no. 7, 073905. DOI: 10.1063/1.4929340}} @misc{jepsen_h2speichersysteme_auf_2015, author={Jepsen, J.}, title={H2-Speichersysteme auf Basis von Leichtmetall-Hydriden - Eine wirtschaftliche und technische Bewertung}, year={2015}, howpublished = {journal article}, abstract = {Leichtmetall-Hydride im Detail dargelegt.}, note = {Jepsen, J.: H2-Speichersysteme auf Basis von Leichtmetall-Hydriden - Eine wirtschaftliche und technische Bewertung. HZwei - Das Magazin fuer Wasserstoff und Brennstoffzellen. 2015. vol. 15, no. 1, 12-13.}} @misc{bellostavoncolbe_design_sorption_2015, author={Bellosta von Colbe, J.M., Lozano, G., Metz, O., Buecherl, T., Bormann, R., Klassen, T., Dornheim, M.}, title={Design, sorption behaviour and energy management in a sodium alanate-based lightweight hydrogen storage tank}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2015.01.013}, abstract = {A lightweight tank for hydrogen storage based on four kilograms of sodium alanate was designed, built and tested. An improvement in gravimetric capacity of 83% and 49% in volumetric capacity over a previous tank [1] was achieved. Heat evolution and temperature spikes during hydrogen absorption were studied. Due to the high specific heat of the complex hydride, the storage material itself acts as a heat sink, aiding in the heat management of the system. The first-ever radiography with fast neutrons on an operational complex-hydride based test tank was performed.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2015.01.013} (DOI). Bellosta von Colbe, J.; Lozano, G.; Metz, O.; Buecherl, T.; Bormann, R.; Klassen, T.; Dornheim, M.: Design, sorption behaviour and energy management in a sodium alanate-based lightweight hydrogen storage tank. International Journal of Hydrogen Energy. 2015. vol. 40, no. 7, 2984-2988. DOI: 10.1016/j.ijhydene.2015.01.013}} @misc{chaudhary_thermodynamic_destabilisation_2015, author={Chaudhary, A.-L., Paskevicius, M., Sheppard, D.A., Buckley, C.E.}, title={Thermodynamic destabilisation of MgH2 and NaMgH3 using Group IV elements Si, Ge or Sn}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2014.10.086}, abstract = {The addition of Group IV elements of Si, Ge or Sn to Mg-based hydrides has led to the successful destabilisation of MgH2 or NaMgH3, resulting in hydrogen release at lower temperatures. This is the first time a direct comparison has been made with all the samples prepared and characterised using identical conditions. Pure MgH2 desorbs hydrogen at a pressure of 1 bar at 282 °C, a temperature too high for typical mobile applications. The addition of Group IV metals to MgH2 causes the formation of intermetallic compounds (Mg2Si, Mg2Ge and Mg2Sn) upon hydrogen release. Theoretical calculations show promising thermodynamic equilibrium conditions for these systems. Experimentally, these conditions were difficult to achieve, however, hydrogen desorption results show that Ge has the most significant effect in allowing low temperature hydrogen release, followed by Sn, then Si. It was found that Si also has a beneficial effect on NaMgH3, reducing the desorption temperature.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2014.10.086} (DOI). Chaudhary, A.; Paskevicius, M.; Sheppard, D.; Buckley, C.: Thermodynamic destabilisation of MgH2 and NaMgH3 using Group IV elements Si, Ge or Sn. Journal of Alloys and Compounds. 2015. vol. 623, 109-116. DOI: 10.1016/j.jallcom.2014.10.086}} @misc{pireddu_comparison_of_2015, author={Pireddu, G., Valentoni, A., Bonatto Minella, C., Pistidda, C., Milanese, C., Enzo, S., Mulas, G., Garroni, S.}, title={Comparison of the thermochemical and mechanochemical transformations in the 2NaNH2–MgH2 system}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.11.145}, abstract = {We focus on the chemical transformations involved in the 2NaNH2 + MgH2 system subjected to thermal and mechanical inputs. Transformations occurring on the powder mixture during thermochemical and mechanochemical processes are described by ex-situ X-ray powder diffraction (XRPD), FT-IR spectroscopy, differential scanning calorimetry and manometric measurements. In the thermally activated samples, the reaction take place through the fast formation of Mg(NH2)2 and NaH via metathesis reaction between NaNH2 and MgH2 at 125 °C. FT-IR analysis confirms the presence of unreacted NaNH2 and a new Na-amide phase that could be ascribable to tetramide, Na2Mg(NH2)4. At higher temperature, the formation of new imide-amide phase is detected, stables up to 300 °C. On the other hand when the initial mixture is subjected to mechanochemical processing for longer milling time (50 h), only Mg(NH2)2 and NaH are produced. The hydrogen desorption reaction of the as-milled Mg(NH2)2–NaH mixture starts at 100 °C together with the formation of the NaMg(NH2)(NH) imide-amide phase, equally to the initial mixture.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.11.145} (DOI). Pireddu, G.; Valentoni, A.; Bonatto Minella, C.; Pistidda, C.; Milanese, C.; Enzo, S.; Mulas, G.; Garroni, S.: Comparison of the thermochemical and mechanochemical transformations in the 2NaNH2–MgH2 system. International Journal of Hydrogen Energy. 2015. vol. 40, no. 4, 1829-1835. DOI: 10.1016/j.ijhydene.2014.11.145}} @misc{chaudhary_reaction_kinetic_2015, author={Chaudhary, A.-L., Sheppard, D.A., Paskevicius, M., Pistidda, C., Dornheim, M., Buckley, C.E.}, title={Reaction kinetic behaviour with relation to crystallite/grain size dependency in the Mg–Si–H system}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.actamat.2015.05.046}, abstract = {An empirical understanding of the relationship between crystallite size and reaction kinetics for the dehydrogenation of MgH2 in the presence of Si was determined. MgH2 was combined with Si under different conditions to obtain varying crystallite sizes of both reactants. Thermal analysis and isothermal desorption were undertaken to obtain reaction kinetic information and therefore determine activation energies as well as the rate limiting step for each of the different crystallite sizes. It was found that there is a strong correlation between crystallite size and activation energy for the growth of the Mg2Si phase, however, any correlation between the nucleation (of Mg2Si) activation energy was less evident. Direct measurements of kinetic behaviour from a manometric Sieverts apparatus showed that initial reaction kinetics were fastest when MgH2 was mixed with Si nanoparticles, however, this sample was not able to fully desorb. Data from the Sieverts measurements were then used with well-known theoretical models to determine the rate limiting step of the reaction. The three dimensional Carter–Valensi (or contracting volume) diffusion model could be used to describe the rate limiting step for most of the reactions. These results have led to a proposed mechanism for the formation of Mg2Si during the decomposition reaction.}, note = {Online available at: \url{https://doi.org/10.1016/j.actamat.2015.05.046} (DOI). Chaudhary, A.; Sheppard, D.; Paskevicius, M.; Pistidda, C.; Dornheim, M.; Buckley, C.: Reaction kinetic behaviour with relation to crystallite/grain size dependency in the Mg–Si–H system. Acta Materialia. 2015. vol. 95, 244-253. DOI: 10.1016/j.actamat.2015.05.046}} @misc{wolff_pim_at_2015, author={Wolff, M., Schaper, J., Dahms, M., Ebel, T., Kainer, K.U., Klassen, T.}, title={PIM at Euro PM2014: Magnesium powder injection moulding for biomedical application}, year={2015}, howpublished = {journal article}, abstract = {excellent biodegradability and biocompatibility. Dr David Whittaker reviews the paper for PIM International.}, note = {Wolff, M.; Schaper, J.; Dahms, M.; Ebel, T.; Kainer, K.; Klassen, T.: PIM at Euro PM2014: Magnesium powder injection moulding for biomedical application. Powder Injection Moulding International. 2015. vol. 9, no. 1, 61-64.}} @misc{hansen_in_situ_2015, author={Hansen, B.R.S., Moeller, K.T., Paskevicius, M., Dippel, A.-C., Walter, P., Webb, C.J., Pistidda, C., Bergemann, N., Dornheim, M., Klassen, T., Joergensen, J.-E., Jensen, T.R.}, title={In situ X-ray diffraction environments for high-pressure reactions}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S1600576715011735}, abstract = {New sample environments and techniques specifically designed for in situ powder X-ray diffraction studies up to 1000 bar (1 bar = 105 Pa) gas pressure are reported and discussed. The cells can be utilized for multiple purposes in a range of research fields. Specifically, investigations of gas-solid reactions and sample handling under inert conditions are undertaken here. Sample containers allowing the introduction of gas from one or both ends are considered, enabling the possibility of flow-through studies. Various containment materials are evaluated, e.g. capillaries of single-crystal sapphire (Al2O3), quartz glass (SiO2), stainless steel (S316) and glassy carbon (Sigradur K), and burst pressures are calculated and tested for the different tube materials. In these studies, high hydrogen pressure is generated with a metal hydride hydrogen compressor mounted in a closed system, which allows reuse of the hydrogen gas. The advantages and design considerations of the in situ cells are discussed and their usage is illustrated by a case study.}, note = {Online available at: \url{https://doi.org/10.1107/S1600576715011735} (DOI). Hansen, B.; Moeller, K.; Paskevicius, M.; Dippel, A.; Walter, P.; Webb, C.; Pistidda, C.; Bergemann, N.; Dornheim, M.; Klassen, T.; Joergensen, J.; Jensen, T.: In situ X-ray diffraction environments for high-pressure reactions. Journal of Applied Crystallography. 2015. vol. 48, no. 4, 1234-1241. DOI: 10.1107/S1600576715011735}} @misc{suarezalcantara_on_the_2015, author={Suarez-Alcantara, K., Boesenberg, U., Saldan, I., Klassen, T., Dornheim, M.}, title={On the Hydrogenation of a NaH/AlB2 Mixture}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.jpcc.5b07444}, abstract = {A mixture of 3NaH/AlB2 was prepared by ball-milling; its hydriding reaction was studied between 375–425 °C and 25–50 bar hydrogen pressure by means of volumetric titration. The hydriding reaction was characterized by means of in situ synchrotron radiation powder X-ray diffraction and high-pressure differential scanning calorimetry. Hydriding reaction took place at the molten state, and its reaction products were NaBH4 and Al. The scanning electron microscopy images of the material revealed that the material morphology changes after hydriding. A maximum hydrogen uptake of 4.7 wt % was registered for the hydriding experiment at 425 °C and 50 bar hydrogen pressure. Dehydriding reaction was studied by means of volumetric titration and differential scanning calorimetry. The dehydriding reaction at 425 °C and 1 bar argon pressure registered a release of 2.4 wt %. The low dehydriding level was attributed to the reduction of the available particle surface upon melting of the material during the hydriding reaction.}, note = {Online available at: \url{https://doi.org/10.1021/acs.jpcc.5b07444} (DOI). Suarez-Alcantara, K.; Boesenberg, U.; Saldan, I.; Klassen, T.; Dornheim, M.: On the Hydrogenation of a NaH/AlB2 Mixture. The Journal of Physical Chemistry C. 2015. vol. 119, no. 40, 22826-22831. DOI: 10.1021/acs.jpcc.5b07444}} @misc{dyachenko_tungsten_band_2015, author={Dyachenko, P.N., do Rosario, J.J., Leib, E.W., Petrov, A.Y., Stoermer, M., Weller, H., Vossmeyer, T., Schneider, G.A., Eich, M.}, title={Tungsten band edge absorber/emitter based on a monolayer of ceramic microspheres}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1364/OE.23.0A1236}, abstract = {We report on a band edge absorber/emitter design for high-temperature applications based on an unstructured tungsten substrate and a monolayer of ceramic microspheres. The absorber was fabricated as a monolayer of ZrO2 microparticles on a tungsten layer with a HfO2 nanocoating. The band edge of the absorption is based on critically coupled microsphere resonances. It can be tuned from visible to near-infrared range by varying the diameter of the microparticles. The absorption properties were found to be stable up to 1000°C.}, note = {Online available at: \url{https://doi.org/10.1364/OE.23.0A1236} (DOI). Dyachenko, P.; do Rosario, J.; Leib, E.; Petrov, A.; Stoermer, M.; Weller, H.; Vossmeyer, T.; Schneider, G.; Eich, M.: Tungsten band edge absorber/emitter based on a monolayer of ceramic microspheres. Optics express. 2015. vol. 23, no. 19, A1236-A1244. DOI: 10.1364/OE.23.0A1236}} @misc{aquila_fluence_thresholds_2015, author={Aquila, A., Sobierajski, R., Ozkan, C., Hajkova, V., Burian, T., Chalupsky, J., Juha, L., Stoermer, M., Bajt, S., Klepka, M.T., Dluzewski, P., Morawiec, K., Ohashi, H., Koyama, T., Tono, K., Inubushi, Y., Yabashi, M., Sinn, H., Tschentscher, T., Mancuso, A.P., Gaudin, J.}, title={Fluence thresholds for grazing incidence hard x-ray mirrors}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1063/1.4922380}, abstract = {X-ray Free Electron Lasers (XFELs) have the potential to contribute to many fields of science and to enable many new avenues of research, in large part due to their orders of magnitude higher peak brilliance than existing and future synchrotrons. To best exploit this peak brilliance, these XFEL beams need to be focused to appropriate spot sizes. However, the survivability of X-ray optical components in these intense, femtosecond radiation conditions is not guaranteed. As mirror optics are routinely used at XFEL facilities, a physical understanding of the interaction between intense X-ray pulses and grazing incidence X-ray optics is desirable. We conducted single shot damage threshold fluence measurements on grazing incidence X-ray optics, with coatings of ruthenium and boron carbide, at the SPring-8 Angstrom compact free electron laser facility using 7 and 12 keV photon energies. The damage threshold dose limits were found to be orders of magnitude higher than would naively be expected. The incorporation of energy transport and dissipation via keV level energetic photoelectrons accounts for the observed damage threshold.}, note = {Online available at: \url{https://doi.org/10.1063/1.4922380} (DOI). Aquila, A.; Sobierajski, R.; Ozkan, C.; Hajkova, V.; Burian, T.; Chalupsky, J.; Juha, L.; Stoermer, M.; Bajt, S.; Klepka, M.; Dluzewski, P.; Morawiec, K.; Ohashi, H.; Koyama, T.; Tono, K.; Inubushi, Y.; Yabashi, M.; Sinn, H.; Tschentscher, T.; Mancuso, A.; Gaudin, J.: Fluence thresholds for grazing incidence hard x-ray mirrors. Applied Physics Letters. 2015. vol. 106, no. 24, 241905. DOI: 10.1063/1.4922380}} @misc{kozhevnikov_comparative_study_2015, author={Kozhevnikov, I.V., Filatova, E.O., Sokolov, A.A., Konashuk, A.S., Siewert, F., Stoermer, M., Gaudin, J., Keitel, B., Samoylova, L., Sinn, H.}, title={Comparative study of the X-ray reflectivity and in-depth profile of a-C, B4C and Ni coatings at 0.1-2 keV}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S1600577515000430}, abstract = {The use of soft X-rays near the carbon edge of absorption (270-300 eV) greatly enhances studies in various branches of science. However, the choice of reflecting coatings for mirrors operating in free-electron and X-ray free-electron laser (FEL and XFEL) beamlines in this spectral range is not so evident and experimental justifications of the mirror efficiency are rather limited. In the present paper it is demonstrated experimentally that the reflectivity of B4C- and Ni-coated grazing-incidence mirrors is high enough for their operation in FEL or XFEL beamlines near the carbon K-edge of absorption. The minimal reflectivity of both mirrors proves to exceed 80% near the carbon absorption edge at a grazing angle of 0.6°. An in-depth profile of the chemical elements composing the reflecting coatings is reconstructed based on analysis of a set of reflectivity curves measured versus the grazing angle at different photon energies in the soft X-ray spectral region. This allows us to predict correctly the mirror reflectivity at any X-ray energy and any grazing angle.}, note = {Online available at: \url{https://doi.org/10.1107/S1600577515000430} (DOI). Kozhevnikov, I.; Filatova, E.; Sokolov, A.; Konashuk, A.; Siewert, F.; Stoermer, M.; Gaudin, J.; Keitel, B.; Samoylova, L.; Sinn, H.: Comparative study of the X-ray reflectivity and in-depth profile of a-C, B4C and Ni coatings at 0.1-2 keV. Journal of Synchrotron Radiation. 2015. vol. 22, 348-353. DOI: 10.1107/S1600577515000430}} @misc{puszkiel_effect_of_2015, author={Puszkiel, J.A., Gennari, F.C., Larochette, P.A., Ramallo-Lopez, J.M., Vainio, U., Karimi, F., Pranzas, P.K., Troiani, H., Pistidda, C., Jepsen, J., Tolkiehn, M., Welter, E., Klassen, T., Bellosta von Colbe, J., Dornheim, M.}, title={Effect of Fe additive on the hydrogenation-dehydrogenation properties of 2LiH + MgB2/2LiBH4 + MgH2 system}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jpowsour.2015.02.153}, abstract = {Lithium reactive hydride composite 2LiBH4 + MgH2 (Li-RHC) has been lately investigated owing to its potential as hydrogen storage medium for mobile applications. However, the main problem associated with this material is its sluggish kinetic behavior. Thus, aiming to improve the kinetic properties, in the present work the effect of the addition of Fe to Li-RHC is investigated. The addition of Fe lowers the starting decomposition temperature of Li-RHC about 30 °C and leads to a considerably faster isothermal dehydrogenation rate during the first hydrogen sorption cycle. Upon hydrogenation, MgH2 and LiBH4 are formed whereas Fe appears not to take part in any reaction. Upon the first dehydrogenation, the formation of nanocrystalline, well distributed FeB reduces the overall hydrogen storage capacity of the system. Throughout cycling, the agglomeration of FeB particles causes a kinetic deterioration. An analysis of the hydrogen kinetic mechanism during cycling shows that the hydrogenation and dehydrogenation behavior is influenced by the activity of FeB as heterogeneous nucleation center for MgB2 and its non-homogenous distribution in the Li-RHC matrix.}, note = {Online available at: \url{https://doi.org/10.1016/j.jpowsour.2015.02.153} (DOI). Puszkiel, J.; Gennari, F.; Larochette, P.; Ramallo-Lopez, J.; Vainio, U.; Karimi, F.; Pranzas, P.; Troiani, H.; Pistidda, C.; Jepsen, J.; Tolkiehn, M.; Welter, E.; Klassen, T.; Bellosta von Colbe, J.; Dornheim, M.: Effect of Fe additive on the hydrogenation-dehydrogenation properties of 2LiH + MgB2/2LiBH4 + MgH2 system. Journal of Power Sources. 2015. vol. 284, 606-616. DOI: 10.1016/j.jpowsour.2015.02.153}} @misc{boerries_scattering_influences_2015, author={Boerries, S., Metz, O., Pranzas, P.K., Buecherl, T., Soellradl, S., Dornheim, M., Klassen, T., Schreyer, A.}, title={Scattering influences in quantitative fission neutron radiography for the in situ analysis of hydrogen distribution in metal hydrides}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.nima.2015.06.033}, abstract = {In situ neutron radiography allows for the time-resolved study of hydrogen distribution in metal hydrides. However, for a precise quantitative investigation of a time-dependent hydrogen content within a host material, an exact knowledge of the corresponding attenuation coefficient is necessary. Additionally, the effect of scattering has to be considered as it is known to violate Beer׳s law, which is used to determine the amount of hydrogen from a measured intensity distribution. Within this study, we used a metal hydride inside two different hydrogen storage tanks as host systems, consisting of steel and aluminum. The neutron beam attenuation by hydrogen was investigated in these two different setups during the hydrogen absorption process. A linear correlation to the amount of absorbed hydrogen was found, allowing for a readily quantitative investigation. Further, an analysis of scattering contributions on the measured intensity distributions was performed and is described in detail.}, note = {Online available at: \url{https://doi.org/10.1016/j.nima.2015.06.033} (DOI). Boerries, S.; Metz, O.; Pranzas, P.; Buecherl, T.; Soellradl, S.; Dornheim, M.; Klassen, T.; Schreyer, A.: Scattering influences in quantitative fission neutron radiography for the in situ analysis of hydrogen distribution in metal hydrides. Nuclear Instruments and Methods in Physics Research A. 2015. vol. 797, 158-164. DOI: 10.1016/j.nima.2015.06.033}} @misc{cao_ternary_amides_2015, author={Cao, H., Richter, T.M.M., Pistidda, C., Chaudhary, A.-L., Santoru, A., Gizer, G., Niewa, R., Chen, P., Klassen, T., Dornheim, M.}, title={Ternary Amides Containing Transition Metals for Hydrogen Storage: A Case Study with Alkali Metal Amidozincates}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1002/cssc.201500990}, abstract = {The alkali metal amidozincates Li4[Zn(NH2)4](NH2)2 and K2[Zn(NH2)4] were, to the best of our knowledge, studied for the first time as hydrogen storage media. Compared with the LiNH2–2 LiH system, both Li4[Zn(NH2)4](NH2)2–12 LiH and K2[Zn(NH2)4]–8 LiH systems showed improved rehydrogenation performance, especially K2[Zn(NH2)4]–8 LiH, which can be fully hydrogenated within 30 s at approximately 230 °C. The absorption properties are stable upon cycling. This work shows that ternary amides containing transition metals have great potential as hydrogen storage materials.}, note = {Online available at: \url{https://doi.org/10.1002/cssc.201500990} (DOI). Cao, H.; Richter, T.; Pistidda, C.; Chaudhary, A.; Santoru, A.; Gizer, G.; Niewa, R.; Chen, P.; Klassen, T.; Dornheim, M.: Ternary Amides Containing Transition Metals for Hydrogen Storage: A Case Study with Alkali Metal Amidozincates. ChemSusChem. 2015. vol. 8, no. 22, 3777-3782. DOI: 10.1002/cssc.201500990}} @misc{plerdsranoy_improvement_of_2015, author={Plerdsranoy, P., Wiset, N., Milanese, C., Laipple, D., Marini, A., Klassen, T., Dornheim, M., Gosalawit-Utke, R.}, title={Improvement of thermal stability and reduction of LiBH4/polymer host interaction of nanoconfined LiBH4 for reversible hydrogen storage}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.10.090}, abstract = {Addition of multi-wall carbon nanotube (MWCNT) and NaAlH4 into nanoconfined LiBH4–PcB (poly (methyl methacrylate)–co–butyl methacrylate) for improving thermal stability and reducing LiBH4/PcB interaction is proposed. The greater the amount of gases desorbed due to polymer (PcB) degradation, the less the thermal stability of polymer host. During dehydrogenation of nanoconfined LiBH4–PcB, combination of gases due to PcB degradation is 64.3% with respect to H2 content, while those of nanoconfined samples doped with MWCNT and NaAlH4 are only 9 and 7.9%, respectively. The LiBH4/PcB (i.e., B⋯OCH3) interaction is quantitatively evaluated by FTIR technique. The more the ratio of peak area between υ(B–H) (from LiBH4) and υ(CO) (from PcB), the lower the LiBH4/PcB interaction. It is found that by adding small amount of MWCNT and NaAlH4, this ratio significantly increases up to 78%. This is in agreement with B 1s XPS results, where the relative amount of BxOy (x/y = 3) to LiBH4 decreases after adding MWCNT and NaAlH4 into nanoconfined LiBH4–PcB. It should be remarked that significant improvement of thermal stability and decrease of LiBH4/PcB interaction after adding MWCNT and NaAlH4 into nanoconfined LiBH4–PcB result in considerable amount of hydrogen release and uptake as well as hydrogen reproducibility during cycling. However, the dispersion of MWCNT is still one of the most critical factors to be concerned due to probably its hindrance for hydrogen diffusion.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.10.090} (DOI). Plerdsranoy, P.; Wiset, N.; Milanese, C.; Laipple, D.; Marini, A.; Klassen, T.; Dornheim, M.; Gosalawit-Utke, R.: Improvement of thermal stability and reduction of LiBH4/polymer host interaction of nanoconfined LiBH4 for reversible hydrogen storage. International Journal of Hydrogen Energy. 2015. vol. 40, no. 1, 392-402. DOI: 10.1016/j.ijhydene.2014.10.090}} @misc{karimi_structural_and_2015, author={Karimi, F., Pranzas, P.K., Pistidda, C., Puszkiel, J.A., Milanese, C., Vainio, U., Paskevicius, M., Emmler, T., Santoru, A., Utke, R., Tolkiehn, M., Minella, C.B., Chaudhary, A.-L., Boerries, S., Buckley, C.E., Enzo, S., Schreyer, A., Klassen, T., Dornheim, M.}, title={Structural and kinetic investigation of the hydride composite Ca(BH4)2 + MgH2 system doped with NbF5 for solid-state hydrogen storage}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c5cp03557k}, abstract = {Designing safe, compact and high capacity hydrogen storage systems is the key step towards introducing a pollutant free hydrogen technology into a broad field of applications. Due to the chemical bonds of hydrogen–metal atoms, metal hydrides provide high energy density in safe hydrogen storage media. Reactive hydride composites (RHCs) are a promising class of high capacity solid state hydrogen storage systems. Ca(BH4)2 + MgH2 with a hydrogen content of 8.4 wt% is one of the most promising members of the RHCs. However, its relatively high desorption temperature of ∼350 °C is a major drawback to meeting the requirements for practical application. In this work, by using NbF5 as an additive, the dehydrogenation temperature of this RHC was significantly decreased. To elucidate the role of NbF5 in enhancing the desorption properties of the Ca(BH4)2 + MgH2 (Ca-RHC), a comprehensive investigation was carried out via manometric measurements, mass spectrometry, Differential Scanning Calorimetry (DSC), in situ Synchrotron Radiation-Powder X-ray Diffraction (SR-PXD), X-ray Absorption Spectroscopy (XAS), Anomalous Small-Angle X-ray Scattering (ASAXS), Scanning and Transmission Electron Microscopy (SEM, TEM) and Nuclear Magnetic Resonance (NMR) techniques.}, note = {Online available at: \url{https://doi.org/10.1039/c5cp03557k} (DOI). Karimi, F.; Pranzas, P.; Pistidda, C.; Puszkiel, J.; Milanese, C.; Vainio, U.; Paskevicius, M.; Emmler, T.; Santoru, A.; Utke, R.; Tolkiehn, M.; Minella, C.; Chaudhary, A.; Boerries, S.; Buckley, C.; Enzo, S.; Schreyer, A.; Klassen, T.; Dornheim, M.: Structural and kinetic investigation of the hydride composite Ca(BH4)2 + MgH2 system doped with NbF5 for solid-state hydrogen storage. Physical Chemistry Chemical Physics. 2015. vol. 17, no. 41, 27328-27342. DOI: 10.1039/c5cp03557k}} @misc{torre_kinetic_improvement_2015, author={Torre, F., Valentoni, A., Milanese, C., Pistidda, C., Marini, A., Dornheim, M., Enzo, S., Mulas, G., Garroni, S.}, title={Kinetic improvement on the CaH2-catalyzed Mg(NH2)2 + 2LiH system}, year={2015}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2014.12.228}, abstract = {In the present work we focused on the catalytic effect of CaH2 on the dehydrogenation process of the Mg(NH2)2–2LiH system. The synthesis, hydrogen storage properties and energy barriers were investigated by X-ray diffraction (XRD), temperature-programmed desorption (TPD) and differential scanning calorimetry (DSC). The TPD measurements proved that desorption of the Mg(NH2)2–2LiH system milled with 0.08 mol of CaH2 started at temperature of 78 °C, lower if compared with the 125 °C observed in the pristine material. Furthermore, Kissinger analysis revealed that CaH2 acted as a catalyst to decrease the activation energy of the first dehydrogenation step from a value of 133.8 ± 4.1 kJ/mol for the pristine material to 105.1 ± 3.2 kJ/mol when CaH2 was dispersed into the mixture.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2014.12.228} (DOI). Torre, F.; Valentoni, A.; Milanese, C.; Pistidda, C.; Marini, A.; Dornheim, M.; Enzo, S.; Mulas, G.; Garroni, S.: Kinetic improvement on the CaH2-catalyzed Mg(NH2)2 + 2LiH system. Journal of Alloys and Compounds. 2015. vol. 645, no. 1, S 284-S 287. DOI: 10.1016/j.jallcom.2014.12.228}} @misc{siewert_on_the_2014, author={Siewert, F., Buchheim, J., Zeschke, T., Stoermer, M., Falkenberg, G., Sankari, R.}, title={On the characterization of ultra-precise X-ray optical components: advances and challenges in ex situ metrology}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S1600577514016221}, abstract = {To fully exploit the ultimate source properties of the next-generation light sources, such as free-electron lasers (FELs) and diffraction-limited storage rings (DLSRs), the quality requirements for gratings and reflective synchrotron optics, especially mirrors, have significantly increased. These coherence-preserving optical components for high-brightness sources will feature nanoscopic shape accuracies over macroscopic length scales up to 1000 mm. To enable high efficiency in terms of photon flux, such optics will be coated with application-tailored single or multilayer coatings. Advanced thin-film fabrication of today enables the synthesis of layers on the sub-nanometre precision level over a deposition length of up to 1500 mm. Specifically dedicated metrology instrumentation of comparable accuracy has been developed to characterize such optical elements. Second-generation slope-measuring profilers like the nanometre optical component measuring machine (NOM) at the BESSY-II Optics laboratory allow the inspection of up to 1500 mm-long reflective optical components with an accuracy better than 50 nrad r.m.s. Besides measuring the shape on top of the coated mirror, it is of particular interest to characterize the internal material properties of the mirror coating, which is the domain of X-rays. Layer thickness, density and interface roughness of single and multilayer coatings are investigated by means of X-ray reflectometry. In this publication recent achievements in the field of slope measuring metrology are shown and the characterization of different types of mirror coating demonstrated. Furthermore, upcoming challenges to the inspection of ultra-precise optical components designed to be used in future FEL and DLSR beamlines are discussed.}, note = {Online available at: \url{https://doi.org/10.1107/S1600577514016221} (DOI). Siewert, F.; Buchheim, J.; Zeschke, T.; Stoermer, M.; Falkenberg, G.; Sankari, R.: On the characterization of ultra-precise X-ray optical components: advances and challenges in ex situ metrology. Journal of Synchrotron Radiation. 2014. vol. 21, no. 5, 968-975. DOI: 10.1107/S1600577514016221}} @misc{chaudhary_mechanochemical_synthesis_2014, author={Chaudhary, A.-L., Sheppard, D.A., Paskevicius, M., Saunders, M., Buckley, C.E.}, title={Mechanochemical synthesis of amorphous silicon nanoparticles}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c3ra47431c}, abstract = {Silicon nanoparticles have been synthesised using mechanochemical ball milling and an inert salt buffer to limit the growth and control the size of the Si particles produced. The solid–liquid metathesis reaction used silicon tetrachloride and lithium with LiCl as the buffer to generate Si nanoparticles. Once the LiCl was removed, X-ray amorphous Si was identified using electron energy loss spectra, at 99 eV and energy filtered transmission electron microscopy. The morphological analysis showed spherical like particles with an average size between 10–30 nm depending on the amount of salt buffer phase added to the reactants. This synthesis method can be used to produce very small Si particles in tuneable sizes for a wide range of applications.}, note = {Online available at: \url{https://doi.org/10.1039/c3ra47431c} (DOI). Chaudhary, A.; Sheppard, D.; Paskevicius, M.; Saunders, M.; Buckley, C.: Mechanochemical synthesis of amorphous silicon nanoparticles. RSC Advances. 2014. vol. 4, no. 42, 21979-21983. DOI: 10.1039/c3ra47431c}} @misc{chaudhary_mg2si_nanoparticle_2014, author={Chaudhary, A.-L., Sheppard, D.A., Paskevicius, M., Webb, C.J., Gray, E.M.A., Buckley, C.E.}, title={Mg2Si Nanoparticle Synthesis for High Pressure Hydrogenation}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp408650g}, abstract = {The Mg–Si–H system is economically favorable as a hydrogen storage medium for renewable energy systems while moving toward sustainable energy production. Hydrogen desorption from MgH2 in the presence of Si is achievable, forming magnesium silicide (Mg2Si). However, absorbing hydrogen into Mg2Si remains problematic due to severe kinetic limitations. The objective of this study is to reduce these kinetic limitations by synthesizing Mg2Si nanoparticles to limit the migration distance for magnesium atoms from the Mg2Si matrix to produce MgH2 and Si, thus improving the reversibility of the Mg–Si–H system. Mg2Si nanoparticles were synthesized using a reduction reaction undertaken by solid–liquid mechanochemical ball milling. Particle size was controlled by adding a reaction buffer (lithium chloride) to the starting reagents to restrict particle growth during milling. The reaction buffer was removed from the nanoparticles using tetrahydrofuran and small-angle X-ray scattering revealed an average Mg2Si particle size of ∼10 nm, the smallest Mg2Si nanoparticles synthesized to date. High-pressure hydrogen measurements were undertaken above thermodynamic equilibrium at a range of temperatures to attempt hydrogen absorption into the Mg2Si nanoparticles. X-ray diffraction results indicate that partial hydrogen absorption took place. Under these absorption conditions bulk Mg2Si cannot absorb hydrogen, demonstrating the kinetic benefit of nanoscopic Mg2Si.}, note = {Online available at: \url{https://doi.org/10.1021/jp408650g} (DOI). Chaudhary, A.; Sheppard, D.; Paskevicius, M.; Webb, C.; Gray, E.; Buckley, C.: Mg2Si Nanoparticle Synthesis for High Pressure Hydrogenation. The Journal of Physical Chemistry C. 2014. vol. 118, no. 2, 1240-1247. DOI: 10.1021/jp408650g}} @misc{wolff_magnesium_powder_2014, author={Wolff, M., Schaper, J.G., Dahms, M., Ebel, T., Kainer, K.U., Klassen, T.}, title={Magnesium powder injection moulding for biomedical application}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1179/1743290114Y.0000000111}, abstract = {Currently, commercial biodegradable implants are mainly made from degradable polymers, such as polyglycolic acid or polylactide acid (PLA). These polymer implants, produced by injection moulding technique, suffer from long degradation times between 18 and 36 months, poor mechanical properties and acidic degradation behaviour. On the other hand, magnesium alloys are drawing increasing interest as biodegradable medical implant material for orthopaedic applications in bone tissue; thus, a replacement of polymers by Mg would be attractive. The production of biomedical and biodegradable Mg alloy parts and implants by powder metallurgy and metal injection moulding (MIM) respectively offers the opportunity for economic manufacturing of parts with mechanical properties matching those of cortical bone tissue, as well as the provision of porous surface structures beneficial for cell ingrowth and vascularisation. Furthermore, the technique guarantees a homogenous microstructure being crucial for a predictable degradation process. This study shows how magnesium powder can be processed successfully by MIM. Recent magnesium alloy implant prototypes and tensile test specimen, produced by MIM technique, provide strength and stiffness twice as high compared to modern polymer based implants. Ultimate tensile strength (UTS) of 131 MPa, yield strength of 64 MPa, residual porosity of 2–6% and elastic modulus of 46 GPa, measured by dynamic method, were achieved under application of special sintering technique and sintering atmosphere control. The paper is focussing on sintering methods and porosity control and measurement.}, note = {Online available at: \url{https://doi.org/10.1179/1743290114Y.0000000111} (DOI). Wolff, M.; Schaper, J.; Dahms, M.; Ebel, T.; Kainer, K.; Klassen, T.: Magnesium powder injection moulding for biomedical application. Powder Metallurgy. 2014. vol. 57, no. 5, 331-340. DOI: 10.1179/1743290114Y.0000000111}} @misc{boesenberg_characterization_of_2014, author={Boesenberg, U., Pistidda, C., Tolkiehn, M., Busch, N., Saldan, I., Suarez-Alcantara, K., Arendarska, A., Klassen, T., Dornheim, M.}, title={Characterization of metal hydrides by in-situ XRD}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.02.068}, abstract = {In-situ synchrotron radiation powder X-ray diffraction (SR-PXD) technique is a powerful tool to gain a deeper understanding of reaction mechanisms in crystalline materials. In this paper, the implementation of a new in-situ SR-PXD cell for solid–gas reactions is described in detail. The cell allows performing measurements in a range of pressure which goes from light vacuum (10−2 bar) up to 200 bar and temperatures from room temperature up to 550 °C. The high precision, with which pressure and temperature are measured, enables to estimate the thermodynamic properties of the observed changes in the crystal structure and phase transformations.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.02.068} (DOI). Boesenberg, U.; Pistidda, C.; Tolkiehn, M.; Busch, N.; Saldan, I.; Suarez-Alcantara, K.; Arendarska, A.; Klassen, T.; Dornheim, M.: Characterization of metal hydrides by in-situ XRD. International Journal of Hydrogen Energy. 2014. vol. 39, no. 18, 9899-9903. DOI: 10.1016/j.ijhydene.2014.02.068}} @misc{soru_structural_evolution_2014, author={Soru, S., Taras, A., Pistidda, C., Milanese, C., Bonatto Minella, C., Masolo, E., Nolis, P., Baro, M.D., Marini, A., Tolkiehn, M., Dornheim, M., Enzo, S., Mulas, G., Garroni, S.}, title={Structural evolution upon decomposition of the LiAlH4 + LiBH4 system}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jallcom.2013.12.027}, abstract = {In the present work we focus the attention on the phase structural transformations occurring upon the desorption process of the LiBH4 + LiAlH4 system. This study is conducted by means of manometric–calorimetric, in situ Synchrotron Radiation Powder X-ray Diffraction (SR-PXD) and exsitu Solid State Magic Angle Spinning (MAS) Nuclear Magnetic Resonance (NMR) measurements. The desorption reaction is characterized by two main dehydrogenation steps starting at 320 and 380 °C, respectively. The first step corresponds to the decomposition of LiAlH4 into Al and H2via the formation of Li3AlH6 whereas the second one refers to the dehydrogenation of LiBH4 (molten state). In the range 328–380 °C, the molten LiBH4 reacts with metallic Al releasing hydrogen and forming an unidentified phase which appears to be an important intermediate for the desorption mechanism of LiBH4–Al-based systems. Interestingly, NMR studies indicate that the unknown intermediate is stable up to 400 °C and it is mainly composed of Li, B, Al and H. In addition, the NMR measurements of the annealed powders (400 °C) confirm that the desorption reaction of the LiBH4 + Al system proceeds via an amorphous boron compound.}, note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2013.12.027} (DOI). Soru, S.; Taras, A.; Pistidda, C.; Milanese, C.; Bonatto Minella, C.; Masolo, E.; Nolis, P.; Baro, M.; Marini, A.; Tolkiehn, M.; Dornheim, M.; Enzo, S.; Mulas, G.; Garroni, S.: Structural evolution upon decomposition of the LiAlH4 + LiBH4 system. Journal of Alloys and Compounds. 2014. vol. 615, no. S1, S 693-S 697. DOI: 10.1016/j.jallcom.2013.12.027}} @misc{masolo_mesoporous_titania_2014, author={Masolo, E., Meloni, M., Garroni, S., Mulas, G., Enzo, S., Baro, M.D., Rossinyol, E., Rzeszutek, A., Herrmann-Geppert, I., Pilo, M.}, title={Mesoporous Titania Powders: The Role of Precursors, Ligand Addition and Calcination Rate on Their Morphology, Crystalline Structure and Photocatalytic Activity}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.3390/nano4030583}, abstract = {We evaluate the influence of the use of different titania precursors, calcination rate, and ligand addition on the morphology, texture and phase content of synthesized mesoporous titania samples, parameters which, in turn, can play a key role in titania photocatalytic performances. The powders, obtained through the evaporation-induced self-assembly method, are characterized by means of ex situ X-Ray Powder Diffraction (XRPD) measurements, N2 physisorption isotherms and transmission electron microscopy. The precursors are selected basing on two different approaches: the acid-base pair, using TiCl4 and Ti(OBu)4, and a more classic route with Ti(OiPr)4 and HCl. For both precursors, different specimens were prepared by resorting to different calcination rates and with and without the addition of acetylacetone, that creates coordinated species with lower hydrolysis rates, and with different calcination rates. Each sample was employed as photoanode and tested in the water splitting reaction by recording I-V curves and comparing the results with commercial P25 powders. The complex data framework suggests that a narrow pore size distribution, due to the use of acetylacetone, plays a major role in the photoactivity, leading to a current density value higher than that of P25.}, note = {Online available at: \url{https://doi.org/10.3390/nano4030583} (DOI). Masolo, E.; Meloni, M.; Garroni, S.; Mulas, G.; Enzo, S.; Baro, M.; Rossinyol, E.; Rzeszutek, A.; Herrmann-Geppert, I.; Pilo, M.: Mesoporous Titania Powders: The Role of Precursors, Ligand Addition and Calcination Rate on Their Morphology, Crystalline Structure and Photocatalytic Activity. Nanomaterials. 2014. vol. 4, no. 3, 583-598. DOI: 10.3390/nano4030583}} @misc{karimi_structural_analysis_2014, author={Karimi, F., Pranzas, P.K., Hoell, A., Vainio, U., Welter, E., Raghuwanshi, V.S., Pistidda, C., Dornheim, M., Klassen, T., Schreyer, A.}, title={Structural analysis of calcium reactive hydride composite for solid state hydrogen storage}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1107/S1600576713031567}, abstract = {Owing to a theoretical hydrogen storage capacity of 10.5 wt% H2, Ca(BH4)2+MgH2, the so-called calcium reactive hydride composite (Ca-RHC), has a great potential as a hydrogen storage material. However, its dehydrogenation temperature (623 K) is too high for any mobile applications. By addition of 10 mol% of NbF5 into Ca(BH4)2+MgH2, a decrease of the dehydrogenation onset temperature by 120 K is observed. In order to understand the reasons behind this desorption temperature decrement two sets of samples [Ca(BH4)2+MgH2 and Ca(BH4)2+MgH2+0.1NbF5] in different hydrogenation states, were prepared. The structural investigation of the above mentioned sets of samples by means of volumetric measurements, anomalous small-angle X-ray scattering (ASAXS) and X-ray absorption spectroscopy (XAS) is reported here. The XAS results show that after the milling procedure NbB2 is formed and remains stable upon further de/rehydrogenation cycling. The results of Nb ASAXS point to nanometric spherical NbB2 particles distributed in the hydride matrix, with a mean diameter of 10 nm. Results from Ca ASAXS indicate Ca-containing nanostructures in the Ca-RHC+0.1NbF5 samples to be 50% finer compared to those without additive. Thus, a higher reaction surface area and shorter diffusion paths for the constituents are concluded to be important contributions to the catalytic effect of an NbF5 additive on the hydrogen sorption kinetics of the Ca(BH4)2+MgH2 composite system.}, note = {Online available at: \url{https://doi.org/10.1107/S1600576713031567} (DOI). Karimi, F.; Pranzas, P.; Hoell, A.; Vainio, U.; Welter, E.; Raghuwanshi, V.; Pistidda, C.; Dornheim, M.; Klassen, T.; Schreyer, A.: Structural analysis of calcium reactive hydride composite for solid state hydrogen storage. Journal of Applied Crystallography. 2014. vol. 47, no. 1, 67-75. DOI: 10.1107/S1600576713031567}} @misc{herrmanngeppert_cold_gas_2014, author={Herrmann-Geppert, I., Bogdanoff, P., Gutzmann, H., Dittrich, T., Emmler, T., just, R., Schieda, M., Gaertner, F., Klassen, T.}, title={Cold Gas Sprayed TiO2-Based Electrodes for the Photo-Induced Water Oxidation}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1149/05830.0021ecst}, abstract = {Cold gas spraying (CGS) is presented as an innovative approach to deposit semiconductor particles onto substrates in order to form photoelectrodes for electrochemical applications. Thin layers of TiO2 (P25-20 by Evonik Industries) are deposited onto titanium substrates (TiO2-CGS films) at different temperatures of the gas carrier within the CGS process (300 - 1000 °C). Structural characterization reveals unchanged bulk properties of the TiO2 nanoparticles. Clearly, the short duration time of the CGS process hinders crystalline bulk changes of the TiO2 particles in the hot gas stream. However, surface photovoltage measurements indicate that the CGS process modified defect states at the surface when exposed to different gas temperature. In photoelectrochemical measurements TiO2-CGS films yield seven times higher photocurrents and IPCE values than comparable films prepared by the well-established doctor blade technique. The increased efficiency might be due to an enhanced particle to substrate bonding caused by particles welding to the metallic substrate during the cold gas spray process.}, note = {Online available at: \url{https://doi.org/10.1149/05830.0021ecst} (DOI). Herrmann-Geppert, I.; Bogdanoff, P.; Gutzmann, H.; Dittrich, T.; Emmler, T.; just, R.; Schieda, M.; Gaertner, F.; Klassen, T.: Cold Gas Sprayed TiO2-Based Electrodes for the Photo-Induced Water Oxidation. ECS Transactions. 2014. vol. 58, no. 30, 21-30. DOI: 10.1149/05830.0021ecst}} @misc{kramm_effect_of_2014, author={Kramm, U.I., Herrmann-Geppert, I., Fiechter, S., Zehl, G., Zizak, I., Dorbrandt, I., Schmeisser, D., Bogdanoff, P.}, title={Effect of iron-carbide formation on the number of active sites in Fe–N–C catalysts for the oxygen reduction reaction in acidic media}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c3ta13821f}, abstract = {In this work Fe–N–C catalysts were prepared by the oxalate-supported pyrolysis of FeTMPPCl or H2TMPP either in the presence or absence of sulfur. The well-known enhancing effect of sulfur-addition on the oxygen reduction activity was confirmed for these porphyrin precursors. The pyrolysis process was monitored in situ by high-temperature X-ray diffraction under synchrotron radiation (HT-XRD) and thermogravimetry coupled with mass-spectroscopy (TG-MS). It was found that the beneficial effect of sulfur could be attributed to the prevention of iron-carbide formation during the heat-treatment process. In the case of pyrolysis of the sulfur-free precursors an excessive iron-carbide formation leads to disintegration of FeN4-centers, hence limiting the number of ORR active sites on the final catalyst. Physical characterization of the catalysts by bulk elemental analysis, X-ray diffraction (XRD), Raman and 57Fe Mößbauer spectroscopy confirmed the outcome from HT-XRD and TG-MS. It could be shown that the avoidance of carbide formation during pyrolysis represents a promising way to enhance the density of ORR active sites on those catalysts. This can be done either by sulfur-addition or the performance of an intermediate acid leaching. As iron carbide is often found as a by-product in the preparation of Fe–N–C catalysts this work gives some general strategies for enhancing the density of active sites enabling higher current densities.}, note = {Online available at: \url{https://doi.org/10.1039/c3ta13821f} (DOI). Kramm, U.; Herrmann-Geppert, I.; Fiechter, S.; Zehl, G.; Zizak, I.; Dorbrandt, I.; Schmeisser, D.; Bogdanoff, P.: Effect of iron-carbide formation on the number of active sites in Fe–N–C catalysts for the oxygen reduction reaction in acidic media. Journal of Materials Chemistry A. 2014. vol. 2, no. 8, 2663-2670. DOI: 10.1039/c3ta13821f}} @misc{napolitano_crystal_structure_2014, author={Napolitano, E., Dolci, F., Campesi, R., Pistidda, C., Hoelzel, M., Moretto, P., Enzo, S.}, title={Crystal structure solution of KMg(ND)(ND2): An ordered mixed amide/imide compound}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2013.10.131}, abstract = {Assuming a density of 1.91 g/cm3 the investigation has allowed to locate the four constituting elements distributed in seven different sites into Wyckoff general positions 4(a), for a total of 28 atoms in the unit cell. This is the first example of crystal structure solution of a mixed imide/amide compound appearing during the dehydrogenation process of a potassium containing amide based hydrogen storage material.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2013.10.131} (DOI). Napolitano, E.; Dolci, F.; Campesi, R.; Pistidda, C.; Hoelzel, M.; Moretto, P.; Enzo, S.: Crystal structure solution of KMg(ND)(ND2): An ordered mixed amide/imide compound. International Journal of Hydrogen Energy. 2014. vol. 39, no. 2, 868-876. DOI: 10.1016/j.ijhydene.2013.10.131}} @misc{boehme_b1mobilstor_materials_2014, author={Boehme, B., Bonatto Minella, C., Thoss, F., Lindemann, I., Rosenburg, M., Pistidda, C., Moeller, K.T., Jensen, T.R., Giebeler, L., Baitinger, M., Gutfleisch, O., Ehrenberg, H., Eckert, J., Grin, Y., Schultz, L.}, title={B1-Mobilstor: Materials for Sustainable Energy Storage Techniques – Lithium Containing Compounds for Hydrogen and Electrochemical Energy Storage}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1002/adem.201400182}, abstract = {New material concepts for hydrogen storage and lithium ion batteries are investigated in the joint ECEMP project B1 – Mobilstor. Chemical composition are essential for the performance of a storage material. A certain state of material can be effectively analyzed by in situ methods to obtain a maximum of information. For hydrogen storage the LiNH2[BOND]MgH2 system and as lithium ion battery anode the Ge(cF136) allotrop are highlighted under this issue.}, note = {Online available at: \url{https://doi.org/10.1002/adem.201400182} (DOI). Boehme, B.; Bonatto Minella, C.; Thoss, F.; Lindemann, I.; Rosenburg, M.; Pistidda, C.; Moeller, K.; Jensen, T.; Giebeler, L.; Baitinger, M.; Gutfleisch, O.; Ehrenberg, H.; Eckert, J.; Grin, Y.; Schultz, L.: B1-Mobilstor: Materials for Sustainable Energy Storage Techniques – Lithium Containing Compounds for Hydrogen and Electrochemical Energy Storage. Advanced Engineering Materials. 2014. vol. 16, no. 10, 1189-1195. DOI: 10.1002/adem.201400182}} @misc{gaudin_towards_simultaneous_2014, author={Gaudin, J., Fourment, C., Cho, B.I., Engelhorn, K., Galtier, E., Harmand, M., Leguay, P.M, Lee, H.J., Nagler, B., Nakatsutsumi, M., Ozkan, C., Stoermer, M., Toleikis, S., Tschentscher, T., Heimann, P.A., Dorchies, F.}, title={Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1038/srep04724}, abstract = {The rapidly growing ultrafast science with X-ray lasers unveils atomic scale processes with unprecedented time resolution bringing the so called “molecular movie” within reach. X-ray absorption spectroscopy is one of the most powerful x-ray techniques providing both local atomic order and electronic structure when coupled with ad-hoc theory. Collecting absorption spectra within few x-ray pulses is possible only in a dispersive setup. We demonstrate ultrafast time-resolved measurements of the LIII-edge x-ray absorption near-edge spectra of irreversibly laser excited Molybdenum using an average of only few x-ray pulses with a signal to noise ratio limited only by the saturation level of the detector. The simplicity of the experimental set-up makes this technique versatile and applicable for a wide range of pump-probe experiments, particularly in the case of non-reversible processes.}, note = {Online available at: \url{https://doi.org/10.1038/srep04724} (DOI). Gaudin, J.; Fourment, C.; Cho, B.; Engelhorn, K.; Galtier, E.; Harmand, M.; Leguay, P.; Lee, H.; Nagler, B.; Nakatsutsumi, M.; Ozkan, C.; Stoermer, M.; Toleikis, S.; Tschentscher, T.; Heimann, P.; Dorchies, F.: Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments. Scientific Reports. 2014. vol. 4, 4724. DOI: 10.1038/srep04724}} @misc{ley_complex_hydrides_2014, author={Ley, M.B., Jepsen, L.H., Lee, Y.-S., Cho, Y.W., Bellosta von Colbe, J.M., Dornheim, M., Rokni, M., jensen, J.O., Sloth, M., Filinchuk, Y., Joergensen, J.E., Besenbacher, F., Jensen, T.R.}, title={Complex hydrides for hydrogen storage – New perspectives}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.mattod.2014.02.013}, abstract = {Since the 1970s, hydrogen has been considered as a possible energy carrier for the storage of renewable energy. The main focus has been on addressing the ultimate challenge: developing an environmentally friendly successor for gasoline. This very ambitious goal has not yet been fully reached, as discussed in this review, but a range of new lightweight hydrogen-containing materials has been discovered with fascinating properties. State-of-the-art and future perspectives for hydrogen-containing solids will be discussed, with a focus on metal borohydrides, which reveal significant structural flexibility and may have a range of new interesting properties combined with very high hydrogen densities.}, note = {Online available at: \url{https://doi.org/10.1016/j.mattod.2014.02.013} (DOI). Ley, M.; Jepsen, L.; Lee, Y.; Cho, Y.; Bellosta von Colbe, J.; Dornheim, M.; Rokni, M.; jensen, J.; Sloth, M.; Filinchuk, Y.; Joergensen, J.; Besenbacher, F.; Jensen, T.: Complex hydrides for hydrogen storage – New perspectives. Materials Today. 2014. vol. 17, no. 3, 122-128. DOI: 10.1016/j.mattod.2014.02.013}} @misc{pistidda_effect_of_2014, author={Pistidda, C., Pottmaier, D., Karimi, F., Garroni, S., Rzeszutek, A., Tolkiehn, M., Fichtner, M., Lohstroh, W., Baricco, M., Klassen, T., Dornheim, M.}, title={Effect of NaH/MgB2 ratio on the hydrogen absorption kinetics of the system NaH + MgB2}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.01.105}, abstract = {In this work the effect of the ratio of starting reactants on the hydrogen absorption reaction of the system xNaH + MgB2 is investigated. At a constant hydrogen pressure of 50 bar, depending on the amount of NaH present in the system NaH + MgB2, different hydrogen absorption behaviors are observed. For two system compositions: NaH + MgB2 and 0.5NaH + MgB2, the formation of NaBH4 and MgH2 as only crystalline hydrogenation products is achieved. The relation between the ratio of the starting reactants and the obtained hydrogenation products is discussed in detail.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.01.105} (DOI). Pistidda, C.; Pottmaier, D.; Karimi, F.; Garroni, S.; Rzeszutek, A.; Tolkiehn, M.; Fichtner, M.; Lohstroh, W.; Baricco, M.; Klassen, T.; Dornheim, M.: Effect of NaH/MgB2 ratio on the hydrogen absorption kinetics of the system NaH + MgB2. International Journal of Hydrogen Energy. 2014. vol. 39, no. 10, 5030-5036. DOI: 10.1016/j.ijhydene.2014.01.105}} @misc{pistidda_effect_of_2014, author={Pistidda, C., Karimi, F., Garroni, S., Rzeszutek, A., Bonatto Minella, C., Milanese, C., Le, T.T., Rude, L.H., Skibsted, J., Jensen, T.R., Horstmann, C., Gundlach, C., Tolkiehn, M., Pranzas, P.K., Schreyer, A., Klassen, T., Dornheim, M.}, title={Effect of the Partial Replacement of CaH2 with CaF2 in the Mixed System CaH2 + MgB2}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp508780b}, abstract = {In this work the effect of a partial replacement of CaH2 with CaF2 on the sorption properties of the system CaH2 + MgB2 has been studied. The first five hydrogen absorption and four desorption reactions of the CaH2 + MgB2 and 3CaH2 + CaF2 + 4MgB2 systems were investigated by means of volumetric measurements, high-pressure differential scanning calorimetric technique (HP-DSC), 11B and 19F MAS NMR spectroscopy, and in situ synchrotron radiation powder X-ray diffraction (SR-PXD). It was observed that already during the mixing of the reactants formation of a nonstoichiometric CaF2–xHx solid solution takes place. Formation of the CaF2–xHx solid solution sensibly affects the overall hydrogen sorption reactions of the system CaH2 + MgB2.}, note = {Online available at: \url{https://doi.org/10.1021/jp508780b} (DOI). Pistidda, C.; Karimi, F.; Garroni, S.; Rzeszutek, A.; Bonatto Minella, C.; Milanese, C.; Le, T.; Rude, L.; Skibsted, J.; Jensen, T.; Horstmann, C.; Gundlach, C.; Tolkiehn, M.; Pranzas, P.; Schreyer, A.; Klassen, T.; Dornheim, M.: Effect of the Partial Replacement of CaH2 with CaF2 in the Mixed System CaH2 + MgB2. The Journal of Physical Chemistry C. 2014. vol. 118, no. 49, 28409-28417. DOI: 10.1021/jp508780b}} @misc{lozano_transport_phenomena_2014, author={Lozano, G.A., Bellosta von Colbe, J.M., Klassen, T., Dornheim, M.}, title={Transport phenomena versus intrinsic kinetics: Hydrogen sorption limiting sub-process in metal hydride beds}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.09.035}, abstract = {This paper discusses and compares the different sub-processes that occur during the hydrogen sorption of practical systems based on metal hydrides, i.e. intrinsic kinetics, heat transfer and hydrogen transport. Derived from their modeling equations, a resistance analysis is developed on these hydrogen sorption sub-processes for the first time. This analysis allows quantifying how strongly each sub-process affects the overall sorption kinetics in a hydride bed and thereby the sorption-rate limiting sub-process can be identified. It was found that in the case of the hydrogen absorption of sodium alanate material the heat transfer resistance is the dominant and rate limiting sub-process, with the exception of small geometries. Besides, the resistance due to hydrogen transport is negligible in comparison to the overall absorption resistance. As a consequence, simulations and designs of scaled-up systems based on sodium alanate material always require heat transfer optimization as one of the foremost considerations.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.09.035} (DOI). Lozano, G.; Bellosta von Colbe, J.; Klassen, T.; Dornheim, M.: Transport phenomena versus intrinsic kinetics: Hydrogen sorption limiting sub-process in metal hydride beds. International Journal of Hydrogen Energy. 2014. vol. 39, no. 33, 18952-18957. DOI: 10.1016/j.ijhydene.2014.09.035}} @misc{gosalawitutke_effective_nanoconfinement_2014, author={Gosalawit-Utke, R., Thiangviriya, S., Javadian, P., Laipple, D., Pistidda, C., Bergemann, N., Horstmann, C., Jensen, T.R., Klassen, T., Dornheim, M.}, title={Effective nanoconfinement of 2LiBH4–MgH2 via simply MgH2 premilling for reversible hydrogen storages}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.07.167}, abstract = {To improve nanoconfinement of LiBH4 and MgH2 in carbon aerogel scaffold (CAS), particle size reduction of MgH2 by premilling technique before melt infiltration is proposed. MgH2 is premilled for 5 h prior to milling with LiBH4 and nanoconfinement in CAS to obtained nanoconfined 2LiBH4–premilled MgH2. Significant confinement of both LiBH4 and MgH2 in CAS, confirmed by SEM–EDS–mapping results, is achieved due to MgH2 premilling. Due to effective nanoconfinement, enhancement of CAS:hydride composite weight ratio to 1:1, resulting in increase of hydrogen storage capacity, is possible. Nanoconfined 2LiBH4–premilled MgH2 reveals a single–step dehydrogenation at 345 °C with no B2H6 release, while dehydrogenation of nanoconfined sample without MgH2 premilling performs in multiple steps at elevated temperatures (up to 430 °C) together with considerable amount of B2H6 release. Activation energy (EA) for the main dehydrogenation of nanoconfined 2LiBH4–premilled MgH2 is considerably lower than those of LiBH4 and MgH2 of bulk 2LiBH4–MgH2 (ΔEA = 31.9 and 55.8 kJ/mol with respect to LiBH4 and MgH2, respectively). Approximately twice faster dehydrogenation rate are accomplished after MgH2 premilling. Three hydrogen release (T = 320 °C, P(H2) = 3–4 bar) and uptake (T = 320–325 °C, P(H2) = 84 bar) cycles of nanoconfined 2LiBH4–premilled MgH2 reveal up to 4.96 wt. % H2 (10 wt. % H2 with respect to hydride composite content), while the 1st desorption of nanoconfined sample without MgH2 premilling gives 4.30 wt. % of combined B2H6 and H2 gases. It should be remarked that not only kinetic improvement and B2H6 suppression are obtained by MgH2 premilling, but also the lowest dehydrogenation temperature (T = 320 °C) among other modified 2LiBH4–MgH2 systems is acquired.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.07.167} (DOI). Gosalawit-Utke, R.; Thiangviriya, S.; Javadian, P.; Laipple, D.; Pistidda, C.; Bergemann, N.; Horstmann, C.; Jensen, T.; Klassen, T.; Dornheim, M.: Effective nanoconfinement of 2LiBH4–MgH2 via simply MgH2 premilling for reversible hydrogen storages. International Journal of Hydrogen Energy. 2014. vol. 39, no. 28, 15614-15626. DOI: 10.1016/j.ijhydene.2014.07.167}} @misc{jia_alphafe2o3_films_2014, author={Jia, L., Harbauer, K., Bogdanoff, P., Herrmann-Geppert, I., Ramirez, A., Krol, R.van de, Fiechter, S.}, title={Alpha-Fe2O3 films for photoelectrochemical water oxidation – insights of key performance parameters}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1039/c4ta04720f}, abstract = {We report the deposition of ultra-thin α-Fe2O3 (hematite) films on fluorine-doped tin oxide (FTO) substrates using radio frequency (RF) sputtering, and the investigation of their photoelectrochemical (PEC) performance towards water oxidation. By varying the deposition pressure and time, the film microstructure and morphology could be optimized. The best hematite films having a thickness of about 50 nm exhibited a photocurrent density of 0.59 mA cm−2 at U = 1.23 V vs. RHE and 1.92 mA cm−2 at U = 1.85 V using a tungsten halogen lamp of 40 mW cm−2 light intensity in the wavelength range from 300 to 600 nm. These values are comparable or even higher than those ever measured hematite films (undoped and having no co-catalyst deposited on top of the electrode). Further measurements were explored to investigate the limiting factors in our films for possibly approaching their predicted PEC properties. A detailed analysis reveals that a slow water oxidation reaction and a trapping of charges on the surface, especially at the potential below 1.4 V, are obviously the reasons for the limited PEC performance.}, note = {Online available at: \url{https://doi.org/10.1039/c4ta04720f} (DOI). Jia, L.; Harbauer, K.; Bogdanoff, P.; Herrmann-Geppert, I.; Ramirez, A.; Krol, R.; Fiechter, S.: Alpha-Fe2O3 films for photoelectrochemical water oxidation – insights of key performance parameters. Journal of Materials Chemistry A. 2014. vol. 2, no. 47, 20196-20202. DOI: 10.1039/c4ta04720f}} @misc{gosalawitutke_destabilization_of_2014, author={Gosalawit-Utke, R., Meethom, S., Pistidda, C., Milanese, C., Laipple, D., Saisopa, T., Marini, A., Klassen, T., Dornheim, M.}, title={Destabilization of LiBH4 by nanoconfinement in PMMA–co–BM polymer matrix for reversible hydrogen storage}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.01.078}, abstract = {Destabilization of LiBH4 by nanoconfinement in poly (methyl methacrylate)–co–butyl methacrylate (PMMA–co–BM), denoted as nano LiBH4–PMMA–co–BM, is proposed for reversible hydrogen storage. The onset dehydrogenation temperature of nano LiBH4–PMMA–co–BM is reduced to ∼80 °C (ΔT = 340 and 170 °C as compared with milled LiBH4 and nanoconfined LiBH4 in carbon aerogel, respectively). At 120 °C under vacuum, nano LiBH4–PMMA–co–BM releases 8.8 wt.% H2 with respect to LiBH4 content within 4 h during the 1st dehydrogenation, while milled LiBH4 performs no dehydrogenation at the same temperature and pressure condition. Moreover, nano LiBH4–PMMA–co–BM can be rehydrogenated at the mildest condition (140 °C under 50 bar H2 for 12 h) among other modified LiBH4 reported in the previous literature. Due to the hydrophobicity of PMMA–co–BM host, deterioration of LiBH4 by oxygen and humidity in ambient condition is avoided after nanoconfinement. Although the interaction between LiBH4 and the pendant group of PMMA–co–BM leads to a reduced hydrogen storage capacity, significant destabilization of LiBH4 is accomplished.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.01.078} (DOI). Gosalawit-Utke, R.; Meethom, S.; Pistidda, C.; Milanese, C.; Laipple, D.; Saisopa, T.; Marini, A.; Klassen, T.; Dornheim, M.: Destabilization of LiBH4 by nanoconfinement in PMMA–co–BM polymer matrix for reversible hydrogen storage. International Journal of Hydrogen Energy. 2014. vol. 39, no. 10, 5019-5029. DOI: 10.1016/j.ijhydene.2014.01.078}} @misc{puszkiel_hydrogen_storage_2014, author={Puszkiel, J., Gennari, F.C., Larochette, P.A., Troiani, H.E., Karimi, F., Pistidda, C., Gosalawit-Utke, R., Jepsen, J., Jensen, T.R., Gundlach, C., Tolkiehn, M., Bellosta von Colbe, J., Klassen, T., Dornheim, M.}, title={Hydrogen storage in Mg–LiBH4 composites catalyzed by FeF3}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jpowsour.2014.05.130}, abstract = {Mg–10 mol% LiBH4 composite plus small amounts of FeF3 is investigated in the present work. The presence of LiBH4 during the milling process noticeably modifies the size and morphology of the Mg agglomerates, leading to faster hydrogenation and reaching almost the theoretical hydrogen capacity owing to enhanced hydrogen diffusion mechanism. However, the dehydrogenation of the system at low temperatures (≤300 °C) is still slow. Thus, FeF3 addition is proposed to improve the dehydrogenation kinetic behavior. From experimental results, it is found that the presence of FeF3 results in an additional size reduction of the Mg agglomerates between ∼10 and ∼100 μm and the formation of stable phases such as MgF2, LiF and FeB. The FeB species might have a catalytic effect upon the MgH2 decomposition. As a further result of the FeF3 addition, the Mg–10 mol%LiBH4–5 mol% FeF3 material shows improved dehydrogenation properties: reduced dehydrogenation activation energy, faster hydrogen desorption rate and reversible hydrogen capacities of about 5 wt% at 275 °C.}, note = {Online available at: \url{https://doi.org/10.1016/j.jpowsour.2014.05.130} (DOI). Puszkiel, J.; Gennari, F.; Larochette, P.; Troiani, H.; Karimi, F.; Pistidda, C.; Gosalawit-Utke, R.; Jepsen, J.; Jensen, T.; Gundlach, C.; Tolkiehn, M.; Bellosta von Colbe, J.; Klassen, T.; Dornheim, M.: Hydrogen storage in Mg–LiBH4 composites catalyzed by FeF3. Journal of Power Sources. 2014. vol. 267, 799-811. DOI: 10.1016/j.jpowsour.2014.05.130}} @misc{pistidda_hydrogen_storage_2014, author={Pistidda, C., Bergemann, N., Wurr, J., Rzeszutek, A., Moeller, K.T., Hansen, B.R.S., Garroni, S., Horstmann, C., Milanese, C., Girella, A., Metz, O., Taube, K., Jensen, T.R., Thomas, D., Liermann, H.P., Klassen, T., Dornheim, M.}, title={Hydrogen storage systems from waste Mg alloys}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.jpowsour.2014.07.129}, abstract = {The production cost of materials for hydrogen storage is one of the major issues to be addressed in order to consider them suitable for large scale applications. In the last decades several authors reported on the hydrogen sorption properties of Mg and Mg-based systems. In this work magnesium industrial wastes of AZ91 alloy and Mg-10 wt.% Gd alloy are used for the production of hydrogen storage materials. The hydrogen sorption properties of the alloys were investigated by means of volumetric technique, in situ synchrotron radiation powder X-ray diffraction (SR-PXD) and calorimetric methods. The measured reversible hydrogen storage capacity for the alloys AZ91 and Mg-10 wt.% Gd are 4.2 and 5.8 wt.%, respectively. For the Mg-10 wt.% Gd alloy, the hydrogenated product was also successfully used as starting reactant for the synthesis of Mg(NH2)2 and as MgH2 substitute in the Reactive Hydride Composite (RHC) 2LiBH4 + MgH2. The results of this work demonstrate the concrete possibility to use Mg alloy wastes for hydrogen storage purposes.}, note = {Online available at: \url{https://doi.org/10.1016/j.jpowsour.2014.07.129} (DOI). Pistidda, C.; Bergemann, N.; Wurr, J.; Rzeszutek, A.; Moeller, K.; Hansen, B.; Garroni, S.; Horstmann, C.; Milanese, C.; Girella, A.; Metz, O.; Taube, K.; Jensen, T.; Thomas, D.; Liermann, H.; Klassen, T.; Dornheim, M.: Hydrogen storage systems from waste Mg alloys. Journal of Power Sources. 2014. vol. 270, 554-563. DOI: 10.1016/j.jpowsour.2014.07.129}} @misc{bergemann_naalh4_production_2014, author={Bergemann, N., Pistidda, C., Milanese, C., Girella, A., Hansen, B.R.S., Wurr, J., Bellosta von Colbe, J., Jepsen, J., Jensen, T.R., Marini, A., Klassen, T., Dornheim, M.}, title={NaAlH4 production from waste aluminum by reactive ball milling}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.02.025}, abstract = {Due to its thermodynamic properties and high reversibility, Ti doped sodium alanate is considered as a prototype hydrogen storage material. In this work we show how sodium alanate can be synthesized by reactive ball milling using aluminum particles obtained from recycled waste incineration slag. The synthesis was monitored with an in situ milling vial and characterized stepwise by PXD and DTA analyses. The sorption properties of the material were investigated using in situ synchrotron radiation PXD and volumetric analyses. A complete conversion of the starting reactants was obtained.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.02.025} (DOI). Bergemann, N.; Pistidda, C.; Milanese, C.; Girella, A.; Hansen, B.; Wurr, J.; Bellosta von Colbe, J.; Jepsen, J.; Jensen, T.; Marini, A.; Klassen, T.; Dornheim, M.: NaAlH4 production from waste aluminum by reactive ball milling. International Journal of Hydrogen Energy. 2014. vol. 39, no. 18, 9877-9882. DOI: 10.1016/j.ijhydene.2014.02.025}} @misc{valentoni_new_insights_2014, author={Valentoni, A., Garroni, S., Pistidda, C., Masolo, E., Napolitano, E., Moretto, P., Dornheim, M., Mulas, G., Enzo, S.}, title={New insights into the thermal desorption of the 2LiNH2 + KBH4 + LiH mixture}, year={2014}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2014.07.169}, abstract = {In situ two-dimensional synchrotron X-ray powder diffraction investigation combined with Rietveld method data analysis were performed in order to yield a complete and quantitative phases structure evolution of the polycrystalline mixture 2LiNH2 + KBH4 + LiH during H2 desorption. While a first-principles, purely thermodynamics approach of the system predicted a single dehydrogenation step reaction at relatively low temperatures, it is assessed experimentally that the reaction occurs in two steps with first the formation of Li2NH at ca. 230 °C due to the reaction between LiNH2 and LiH plus hydrogen and ammonia evolution, followed by an additional reaction of the resulting phases with KBH4 at 360 °C, which releases hydrogen and leads to the formation of the monoclinic and tetragonal Li3BN2 polymorphs. Besides pointing out possible limits of a purely thermodynamics approach inevitably relying exact knowledge of experimental quantities, it is concluded that before assuming it viable for on-board vehicle use, additional stoichiometries may be worth of investigation in order to assess any existence of lower hydrogen desorption temperature of such system.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2014.07.169} (DOI). Valentoni, A.; Garroni, S.; Pistidda, C.; Masolo, E.; Napolitano, E.; Moretto, P.; Dornheim, M.; Mulas, G.; Enzo, S.: New insights into the thermal desorption of the 2LiNH2 + KBH4 + LiH mixture. International Journal of Hydrogen Energy. 2014. vol. 39, no. 30, 17075-17082. DOI: 10.1016/j.ijhydene.2014.07.169}} @misc{gosalawitutke_nanoconfined_2libh4mgh2ticl3_2013, author={Gosalawit-Utke, R., Milanese, C., Javadian, P., Jepsen, J., Laipple, D., Karmi, F., Puszkiel, J., Jensen, T.R., Marini, A., Klassen, T., Dornheim, M.}, title={Nanoconfined 2LiBH4–MgH2–TiCl3 in carbon aerogel scaffold for reversible hydrogen storage}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2012.12.123}, abstract = {Nanoconfinement of 2LiBH4–MgH2–TiCl3 in resorcinol–formaldehyde carbon aerogel scaffold (RF–CAS) for reversible hydrogen storage applications is proposed. RF–CAS is encapsulated with approximately 1.6 wt. % TiCl3 by solution impregnation technique, and it is further nanoconfined with bulk 2LiBH4–MgH2 via melt infiltration. Faster dehydrogenation kinetics is obtained after TiCl3 impregnation, for example, nanoconfined 2LiBH4–MgH2–TiCl3 requires ∼1 and 4.5 h, respectively, to release 95% of the total hydrogen content during the 1st and 2nd cycles, while nanoconfined 2LiBH4–MgH2 (∼2.5 and 7 h, respectively) and bulk material (∼23 and 22 h, respectively) take considerably longer. Moreover, 95–98.6% of the theoretical H2 storage capacity (3.6–3.75 wt. % H2) is reproduced after four hydrogen release and uptake cycles of the nanoconfined 2LiBH4–MgH2–TiCl3. The reversibility of this hydrogen storage material is confirmed by the formation of LiBH4 and MgH2 after rehydrogenation using FTIR and SR-PXD techniques, respectively.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2012.12.123} (DOI). Gosalawit-Utke, R.; Milanese, C.; Javadian, P.; Jepsen, J.; Laipple, D.; Karmi, F.; Puszkiel, J.; Jensen, T.; Marini, A.; Klassen, T.; Dornheim, M.: Nanoconfined 2LiBH4–MgH2–TiCl3 in carbon aerogel scaffold for reversible hydrogen storage. International Journal of Hydrogen Energy. 2013. vol. 38, no. 8, 3275-3282. DOI: 10.1016/j.ijhydene.2012.12.123}} @misc{lang_goldsilicon_metamaterial_2013, author={Lang, S., Lee, H.S., Petrov, A.Y., Stoermer, M., Ritter, M., Eich, M.}, title={Gold-silicon metamaterial with hyperbolic transition in near infrared}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1063/1.4813499}, abstract = {The performance is comparable to other proposed metamaterials.}, note = {Online available at: \url{https://doi.org/10.1063/1.4813499} (DOI). Lang, S.; Lee, H.; Petrov, A.; Stoermer, M.; Ritter, M.; Eich, M.: Gold-silicon metamaterial with hyperbolic transition in near infrared. Applied Physics Letters. 2013. vol. 103, no. 2, 021905. DOI: 10.1063/1.4813499}} @misc{jepsen_compaction_pressure_2013, author={Jepsen, J., Milanese, C., Girella, A., Lozano, G.A., Pistidda, C., Bellosta von Colbe, J.M., Marini, A., Klassen, T., Dornheim, M.}, title={Compaction pressure influence on material properties and sorption behaviour of LiBH4–MgH2 composite}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2013.04.090}, abstract = {Among different Reactive Hydride Composites (RHCs), the combination of LiBH4 and MgH2 is a promising one for hydrogen storage, providing a high reversible storage capacity. During desorption of both LiBH4 and MgH2, the formation of MgB2 lowers the overall reaction enthalpy. In this work, the material was compacted to pellets for further improvement of the volumetric hydrogen capacity. The influence of compaction pressure on the apparent density, thermal conductivity and sorption behaviour for the Li-based RHC during cycling was investigated for the first time. Although LiBH4 melts during cycling, decrepitation or disaggregation of the pellets is not observed for any of the investigated compaction pressures. However, a strong influence of the compaction pressure on the apparent hydrogen storage capacity is detected. The influence on the reaction kinetics is rather low. To provide explanations for the observed correlations, SEM analysis before and after each sorption step was performed for different compaction pressures. Thus, the low hydrogen sorption in the first cycles and the continuously improving sorption for low pressure compacted pellets with cycling may be explained by some surface observations, along with the form stability of the pellets.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2013.04.090} (DOI). Jepsen, J.; Milanese, C.; Girella, A.; Lozano, G.; Pistidda, C.; Bellosta von Colbe, J.; Marini, A.; Klassen, T.; Dornheim, M.: Compaction pressure influence on material properties and sorption behaviour of LiBH4–MgH2 composite. International Journal of Hydrogen Energy. 2013. vol. 38, no. 20, 8357-8366. DOI: 10.1016/j.ijhydene.2013.04.090}} @misc{bonattominella_chemical_state_2013, author={Bonatto Minella, C., Pellicer, E., Rossinyol, E., Karimi, F., Pistidda, C., Garroni, S., Milanese, C., Nolis, P., Baro, M.D., Gutfleisch, O., Pranzas, K.P., Schreyer, A., Klassen, T., Bormann, R., Dornheim, M.}, title={Chemical State, Distribution, and Role of Ti- and Nb-Based Additives on the Ca(BH4)2 System}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp3116275}, abstract = {Light metal tetrahydroborates are regarded as promising materials for solid state hydrogen storage. Due to both a high gravimetric hydrogen capacity of 11.5 wt % and an ideal dehydrogenation enthalpy of 32 kJ mol–1 H2, Ca(BH4)2 is considered to be one of the most interesting compounds in this class of materials. In this work, a comprehensive investigation of the effect of different selected additives (TiF4, NbF5, Ti-isopropoxide, and CaF2) on the reversible hydrogenation reaction of calcium borohydride is presented combining different investigation techniques. The chemical state of the Nb- and Ti-based additives is studied by X-ray absorption spectroscopy (e.g., XANES). Transmission electron microscopy (TEM) coupled with selected area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDX) was used to show the local structure, size, and distribution of the additive/catalyst. 11B{1H} solid state magic angle spinning-nuclear magnetic resonance (MAS NMR) was carried out to detect possible amorphous phases. The formation of TiB2 and NbB2 nanoparticles was observed after milling or upon sorption reactions of the Nb- and Ti-based Ca(BH4)2 doped systems. The formation of transition-metal boride nanoparticles is proposed to support the heterogeneous nucleation of CaB6. The {111}CaB6/{1011}NbB2, {111}CaB6/{1010}NbB2, as well as {111}CaB6/{1011}TiB2 plane pairs have the potential to be the matching planes because the d-value mismatch is well below the d-critical mismatch value (6%). Transition-metal boride nanoparticles act as heterogeneous nucleation sites for CaB6, refine the microstructure thus improving the sorption kinetics, and, as a consequence, lead to the reversible formation of Ca(BH4)2.}, note = {Online available at: \url{https://doi.org/10.1021/jp3116275} (DOI). Bonatto Minella, C.; Pellicer, E.; Rossinyol, E.; Karimi, F.; Pistidda, C.; Garroni, S.; Milanese, C.; Nolis, P.; Baro, M.; Gutfleisch, O.; Pranzas, K.; Schreyer, A.; Klassen, T.; Bormann, R.; Dornheim, M.: Chemical State, Distribution, and Role of Ti- and Nb-Based Additives on the Ca(BH4)2 System. The Journal of Physical Chemistry C. 2013. vol. 117, no. 9, 4394-4403. DOI: 10.1021/jp3116275}} @misc{garroni_mechanochemical_synthesis_2013, author={Garroni, S., Bonatto Minalla, C., Pottmaier, D., Pistidda, C., Milanese, C., Marini, A., Enzo, S., Mulas, G., Dornheim, M., Baricco, M., Gutfleisch, O., Surinach, S., Baro, M.D.}, title={Mechanochemical synthesis of NaBH4 starting from NaHMgB2 reactive hydride composite system}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2012.11.136}, abstract = {The present investigation focuses on a new synthesis route of NaBH4 starting from the 2NaH + MgB2 system subjected to mechanochemical activation under reactive hydrogen atmosphere. The milling process was carried out under two different hydrogen pressures (1 and 120 bar) with two different rotation speeds (300 and 550 rpm). The reaction products were characterized by ex-situ solid state magic angle spinning (MAS) nuclear magnetic resonance (NMR), ex-situ X-ray powder diffraction (XRPD) and Infrared Spectroscopy (IR). From the results of these analyses, it can be concluded that milling in all the considered conditions led to the formation of NaBH4 (cubic-Fm-3m). In particular, a reaction yield of 5 and 14 wt% is obtained after 20 h of milling at 120 bar of H2 for the tests performed at 300 rpm and 550 rpm, respectively. The presence of MgH2 is also detected among the final products on the as milled powders. The influence of the milling conditions and the evaluation of the parameters related the mechanochemical process are here discussed.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2012.11.136} (DOI). Garroni, S.; Bonatto Minalla, C.; Pottmaier, D.; Pistidda, C.; Milanese, C.; Marini, A.; Enzo, S.; Mulas, G.; Dornheim, M.; Baricco, M.; Gutfleisch, O.; Surinach, S.; Baro, M.: Mechanochemical synthesis of NaBH4 starting from NaHMgB2 reactive hydride composite system. International Journal of Hydrogen Energy. 2013. vol. 38, no. 5, 2363-2369. DOI: 10.1016/j.ijhydene.2012.11.136}} @misc{croci_gembased_thermal_2013, author={Croci, G., Claps, G., Caniello, R., Cazzaniga, C., Grosso, G., Murtas, F., Tardocchi, M., Vassallo, E., Gorini, G., Horstmann, C., Kampmann, R., Nowak, G., Stoermer, M.}, title={GEM-based thermal neutron beam monitors for spallation sources}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.nima.2013.05.111}, abstract = {The development of new large area and high flux thermal neutron detectors for future neutron spallation sources, like the European Spallation Source (ESS) is motivated by the problem of 3He shortage. In the framework of the development of ESS, GEM (Gas Electron Multiplier) is one of the detector technologies that are being explored as thermal neutron sensors. A first prototype of GEM-based thermal neutron beam monitor (bGEM) has been built during 2012. The bGEM is a triple GEM gaseous detector equipped with an aluminum cathode coated by View the MathML source1μm thick B4C layer used to convert thermal neutrons to charged particles through the 10B(n,7Li)αα nuclear reaction. This paper describes the results obtained by testing a bGEM detector at the ISIS spallation source on the VESUVIO beamline. Beam profiles (FWHMx=31 mm and FWHMy=36 mm), bGEM thermal neutron counting efficiency (≈1%≈1%), detector stability (3.45%) and the time-of-flight spectrum of the beam were successfully measured. This prototype represents the first step towards the development of thermal neutrons detectors with efficiency larger than 50% as alternatives to 3He-based gaseous detectors.}, note = {Online available at: \url{https://doi.org/10.1016/j.nima.2013.05.111} (DOI). Croci, G.; Claps, G.; Caniello, R.; Cazzaniga, C.; Grosso, G.; Murtas, F.; Tardocchi, M.; Vassallo, E.; Gorini, G.; Horstmann, C.; Kampmann, R.; Nowak, G.; Stoermer, M.: GEM-based thermal neutron beam monitors for spallation sources. Nuclear Instruments and Methods in Physics Research A. 2013. vol. 732, 217-220. DOI: 10.1016/j.nima.2013.05.111}} @misc{gutzmann_cold_spraying_2013, author={Gutzmann, H., Gaertner, F., Hoeche, D., Blawert, C., Klassen, T.}, title={Cold Spraying of Ti2AlC MAX-Phase Coatings}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1007/s11666-012-9843-1}, abstract = {Cold spraying was applied to deposit Ti2AlC on different substrate materials. The study of single impacts by scanning electron microscopy indicates that bonding of the first layer is mainly attributed to the deformation and shear instabilities occurring at substrate sites. Nevertheless, as compared to the feedstock particles, the splats appear flattened by the impact. This deformation seems to be attributed not only to local, internal shear but also to internal fracture. By applying up to five passes under optimized spray parameters, Ti2AlC-coatings with thicknesses of about 110-155 μm were achieved. XRD analysis of the coating proved that the crystallographic structure of the feedstock was retained during cold spraying. The coating microstructures show rather low porosity of about <2%, but several cracks between spray layers. Successful build-up of more than one layer can probably be attributed to local deformation of the highly anisotropic Ti2AlC-phase.}, note = {Online available at: \url{https://doi.org/10.1007/s11666-012-9843-1} (DOI). Gutzmann, H.; Gaertner, F.; Hoeche, D.; Blawert, C.; Klassen, T.: Cold Spraying of Ti2AlC MAX-Phase Coatings. Journal of Thermal Spray Technology. 2013. vol. 22, no. 2-3, 406-412. DOI: 10.1007/s11666-012-9843-1}} @misc{holm_investigations_on_2013, author={Holm, M., Ebel, T., Dahms, M.}, title={Investigations on Ti–6Al–4V with gadolinium addition fabricated by metal injection moulding}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.matdes.2013.05.003}, abstract = {In order to provide this overview, this study shows that it is possible to prepare a reasonable homogeneous powder metallurgical Ti–6Al–4V alloy with Gd additions by using the MIM-technique. Adding Gd to Ti–6Al–4V alloy powder and processing the blend by MIM leads to significant grain refinement and a slight change in pore size and shape. However, strength and ductility are reduced by the addition of Gd.}, note = {Online available at: \url{https://doi.org/10.1016/j.matdes.2013.05.003} (DOI). Holm, M.; Ebel, T.; Dahms, M.: Investigations on Ti–6Al–4V with gadolinium addition fabricated by metal injection moulding. Materials and Design. 2013. vol. 51, 943-948. DOI: 10.1016/j.matdes.2013.05.003}} @misc{moretto_a_round_2013, author={Moretto, P., Zlotea, C., Dolci, F., Amieiro, A., Bobet, J.-L., Borgschulte, A., Chandra, N., Enoki, H., de Rango, P., Fuchart, D., Jepsen, J., Latroche, M., Llamas Jansa, I., Moser, D., Sartori, S., Wang, S.M., Zan, J.A.}, title={A Round Robin Test exercise on hydrogen absorption/desorption properties of a magnesium hydride based material}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2013.03.118}, abstract = {The full hydrogen capacity was found to vary in the range 5.1–6.4 wt.% at 280 °C (553 K) and in the range 5.3–6.6 wt.% at 320 °C (593 K) (value for 1 MPa hydrogen pressure). The relative standard deviations of 6.9% and 7.2%, respectively, were measured for absorption. The absorption plateau pressure of magnesium hydride varies between 0.08 and 0.14 MPa with an average of 0.10 MPa and a relative standard deviation of 17.3% at 280 °C (553 K). At 320 °C (593 K) the absorption plateau pressure results fall in the range 0.26–0.45 MPa, with a relative standard deviation of 17.6%. Kinetics curves were affected by much higher data dispersion than the PCI data. The enthalpy of absorption was −75.7 KJ/moleH2, with a relative standard deviation of 4.4%. The results highlight the importance of well defined measuring and reporting protocols as a base for future standard procedures.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2013.03.118} (DOI). Moretto, P.; Zlotea, C.; Dolci, F.; Amieiro, A.; Bobet, J.; Borgschulte, A.; Chandra, N.; Enoki, H.; de Rango, P.; Fuchart, D.; Jepsen, J.; Llamas Jansa, I.; Moser, D.; Sartori, S.; Wang, S.; Zan, J.: A Round Robin Test exercise on hydrogen absorption/desorption properties of a magnesium hydride based material. International Journal of Hydrogen Energy. 2013. vol. 38, no. 16, 6704-6717. DOI: 10.1016/j.ijhydene.2013.03.118}} @misc{herrmanngeppert_surface_aspects_2013, author={Herrmann-Geppert, I., Bogdanoff, P., Radnik, J., Fengler, S., Dittrich, T., Fiechter, S.}, title={Surface aspects of solgel derived hematite films for the photoelectrochemical oxidation of water}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1039/C2CP42651J}, abstract = {Alpha-Fe2O3 (hematite) photoanodes for the oxygen evolution reaction (OER) were prepared by a cost-efficient sol–gel procedure. Due to low active photoelectrochemical properties observed, it is assumed that the sol–gel procedure leads to hematite films with defects and surface states on which generated charge carriers are recombined or immobilized in trap processes. Electrochemical activation was proven to diminish unfavourable surface groups to some extent. More efficiently, a plasma treatment improves significantly the photoelectrochemical properties of the OER. X-ray photoelectron spectroscopy (XPS) analysis reveals an oxygen enriched surface layer with new oxygen species which may be responsible for the improved electrochemical activity. Due to surface photovoltage an increased fraction of transferred charge carriers from these newly produced surface defects are identified.}, note = {Online available at: \url{https://doi.org/10.1039/C2CP42651J} (DOI). Herrmann-Geppert, I.; Bogdanoff, P.; Radnik, J.; Fengler, S.; Dittrich, T.; Fiechter, S.: Surface aspects of solgel derived hematite films for the photoelectrochemical oxidation of water. Physical Chemistry Chemical Physics. 2013. vol. 15, 1389-1398. DOI: 10.1039/C2CP42651J}} @misc{bonattominella_cabh42__2013, author={Bonatto Minella, C., Pistidda, C., Garroni, S., Nolis, P., Baro, M.D., Gutfleisch, O., Klassen, T., Bormann, R., Dornheim, M.}, title={Ca(BH4)2 + MgH2: Desorption Reaction and Role of Mg on Its Reversibility}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp312271s}, abstract = {The Ca(BH4)2–MgH2 composite system represents a promising candidate for mobile hydrogen storage due to a 10.5 wt % theoretical hydrogen storage capacity and an estimated equilibrium temperature lower than 160 °C. For this system, the reversibility was achieved without further addition of additives. In this study, the decomposition path of the Ca(BH4)2 + MgH2 composite system is investigated in detail by in situ synchrotron radiation powder X-ray diffraction and differential scanning calorimetry combined with thermogravimetry. The sorption properties are analyzed by volumetric measurements. 11B{1H} solid state magic angle spinning–nuclear magnetic resonance was employed for the characterization of the final amorphous or nanocrystalline boron-based decomposition products. This study shows that the intermediate formation of Ca4Mg3H14 upon dehydrogenation of the Ca(BH4)2–MgH2 composite system is not a necessary step, and its presence can be adjusted modifying the preparation procedure. Moreover, the d-value mismatch calculated for the {111}CaB6/{1011}Mg plane pair is the lowest among the other plane pairs considered in the system. The mismatch in the third direction between CaB6 and Mg is also extremely good. These findings propose Mg as a supporter of the heterogeneous nucleation of CaB6 during decomposition of the Ca(BH4)2 + MgH2 composite system.}, note = {Online available at: \url{https://doi.org/10.1021/jp312271s} (DOI). Bonatto Minella, C.; Pistidda, C.; Garroni, S.; Nolis, P.; Baro, M.; Gutfleisch, O.; Klassen, T.; Bormann, R.; Dornheim, M.: Ca(BH4)2 + MgH2: Desorption Reaction and Role of Mg on Its Reversibility. The Journal of Physical Chemistry C. 2013. vol. 117, no. 8, 3846-3852. DOI: 10.1021/jp312271s}} @misc{puszkiel_sorption_behavior_2013, author={Puszkiel, J., Gennari, F., Larochette, P.A., Karimi, F., Pistidda, C., Gosalawit-Utke, R., Jepsen, J., Jensen, T.R., Gundlach, C., Bellosta von Colbe, J., Klassen, T., Dornheim, M.}, title={Sorption behavior of the MgH2–Mg2FeH6 hydride storage system synthesized by mechanical milling followed by sintering}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2013.08.068}, abstract = {The hydrogen sorption behavior of the Mg2FeH6–MgH2 hydride system is investigated via in-situ synchrotron and laboratory powder X-ray diffraction (SR-PXD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), particle size distribution (PSD) and volumetric techniques. The Mg2FeH6–MgH2 hydride system is obtained by mechanical milling in argon atmosphere followed by sintering at high temperature and hydrogen pressure. In-situ SR-PXD results show that upon hydriding MgH2 is a precursor for Mg2FeH6 formation and remained as hydrided phase in the obtained material. Diffusion constraints preclude the further formation of Mg2FeH6. Upon dehydriding, our results suggest that MgH2 and Mg2FeH6 decompose independently in a narrow temperature range between 275 and 300 °C. Moreover, the decomposition behavior of both hydrides in the Mg2FeH6–MgH2 hydride mixture is influenced by each other via dual synergetic-destabilizing effects. The final hydriding/dehydriding products and therefore the kinetic behavior of the Mg2FeH6–MgH2 hydride system exhibits a strong dependence on the temperature and pressure conditions.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2013.08.068} (DOI). Puszkiel, J.; Gennari, F.; Larochette, P.; Karimi, F.; Pistidda, C.; Gosalawit-Utke, R.; Jepsen, J.; Jensen, T.; Gundlach, C.; Bellosta von Colbe, J.; Klassen, T.; Dornheim, M.: Sorption behavior of the MgH2–Mg2FeH6 hydride storage system synthesized by mechanical milling followed by sintering. International Journal of Hydrogen Energy. 2013. vol. 38, no. 34, 14618-14630. DOI: 10.1016/j.ijhydene.2013.08.068}} @misc{pistidda_structural_study_2013, author={Pistidda, C., Napolitano, E., Pottmaier, D., Dornheim, M., Klassen, T., Baricco, M., Enzo, S.}, title={Structural study of a new B-rich phase obtained by partial hydrogenation of 2NaH + MgB2}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2013.06.025}, abstract = {The structure of an unknown crystalline phase observed during the hydrogen absorption reaction of the powder mixtures 2NaH + MgB2 at high pressure has been studied by ab-initio structure determination from powder diffraction. The sequence of un-overlapped peaks extracted from the X-ray powder diffraction pattern could be indexed with a primitive cubic cell with lattice parameter a = 7.319 Å. The diffraction patterns of the peaks are matched with the Pa-3 space group. The stoichiometry of the hydrogen absorption reaction suggests the presence of a high-boron content phase in the compound under investigation. Assuming this phase to be composed only by boron atoms and therefore having a density similar to that found for boron polymorphs, the solution with a space group of Pa-3 leads to reasonable B–B interatomic distances.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2013.06.025} (DOI). Pistidda, C.; Napolitano, E.; Pottmaier, D.; Dornheim, M.; Klassen, T.; Baricco, M.; Enzo, S.: Structural study of a new B-rich phase obtained by partial hydrogenation of 2NaH + MgB2. International Journal of Hydrogen Energy. 2013. vol. 38, no. 25, 10479-10484. DOI: 10.1016/j.ijhydene.2013.06.025}} @misc{gosalawitutke_nanoconfined_2libh4mgh2_2013, author={Gosalawit-Utke, R., Milanese, C., Nielsen, T.K., Karimi, F., Saldan, I., Pranzas, K., Jensen, T.R., Marini, A., Klassen, T., Dornheim, M.}, title={Nanoconfined 2LiBH4–MgH2 for reversible hydrogen storages: Reaction mechanisms, kinetics and thermodynamics}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2012.11.064}, abstract = {Samples of nanoconfined Reactive Hydride Composites in resorcinol–formaldehyde aerogel scaffolds (RF–CAS) are prepared by (i) direct melt infiltration of bulk 2LiBH4–MgH2; and (ii) MgH2 impregnation and LiBH4 melt infiltration. The reaction mechanisms, kinetics and thermodynamics of the systems are concluded. Activation energy (EA) and dehydrogenation enthalpies of LiBH4 and MgH2(ΔHdes,MgH2+ΔHdes,LiBH4) of nanoconfined 2LiBH4–MgH2 are in this work of interest. The hydrogen sorption reactions in both nanoconfined samples are reversible as shown by the recovering of LiBH4 and MgH2 after rehydrogenation. The titration results show the remarkable improvement in desorption kinetics of nanoconfined samples over the bulk material, such as more than 90% of overall hydrogen storage capacity is obtained within 2 h from the nanoconfined samples during the 1st dehydrogenation, while that of bulk material needs more than 16 h. The activation energy of the composites decreases by 27–170 kJ/mol (ΔEA) due to nanoconfinement. For thermodynamics, (ΔHdes,MgH2+ΔHdes,LiBH4) calculated from DSC results of the nanoconfined samples are in the range of 41–46 kJ/mol H2.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2012.11.064} (DOI). Gosalawit-Utke, R.; Milanese, C.; Nielsen, T.; Karimi, F.; Saldan, I.; Pranzas, K.; Jensen, T.; Marini, A.; Klassen, T.; Dornheim, M.: Nanoconfined 2LiBH4–MgH2 for reversible hydrogen storages: Reaction mechanisms, kinetics and thermodynamics. International Journal of Hydrogen Energy. 2013. vol. 38, no. 4, 1932-1942. DOI: 10.1016/j.ijhydene.2012.11.064}} @misc{saldan_hydrogen_sorption_2013, author={Saldan, I., Schulze, M., Pistidda, C., Gosalawit-Utke, R., Zavorotynska, O., Rude, L.H., Skibsted, J., Haase, D., Cerenius, Y., Jensen, T.R., Spoto, G., Baricco, M., Taube, K., Dornheim, M.}, title={Hydrogen Sorption in the LiH–LiF–MgB2 System}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp405856s}, abstract = {A composite material in the LiH–LiF–MgB2 system has been synthesized by high-energy ball milling. Some peaks in addition to that of the binary 2LiH–MgB2 and 2LiF–MgB2 systems are observed for the composite material by high-pressure differential scanning calorimetry (HP-DSC), indicating the formation of intermediate phases. In situ synchrotron radiation powder X-ray diffraction (SR-PXD) performed at 60 bar of H2 and 390 °C shows a superposition of both reaction pathways that are typical for 2LiH–MgB2 and 2LiF–MgB2. After hydrogen absorption of the LiH–LiF–MgB2 composite the vibrational modes of LiBH4 were observed by attenuated total reflection infrared (ATR-IR) spectroscopy. The 19F MAS NMR spectrum of the LiF–LiBH4 sample after heat treatment in hydrogen is strongly dominated by the centerband and spinning sidebands from LiF; in addition, a low-intensity resonance, very similar to that of [BF4] – ion, is identified.}, note = {Online available at: \url{https://doi.org/10.1021/jp405856s} (DOI). Saldan, I.; Schulze, M.; Pistidda, C.; Gosalawit-Utke, R.; Zavorotynska, O.; Rude, L.; Skibsted, J.; Haase, D.; Cerenius, Y.; Jensen, T.; Spoto, G.; Baricco, M.; Taube, K.; Dornheim, M.: Hydrogen Sorption in the LiH–LiF–MgB2 System. The Journal of Physical Chemistry C. 2013. vol. 117, no. 33, 17360-17366. DOI: 10.1021/jp405856s}} @misc{suryanarayana_mechanical_characterization_2013, author={Suryanarayana, C., Behn, R., Klassen, T., Bormann, R.}, title={Mechanical characterization of mechanically alloyed ultrafine-grained Ti5Si3+40 vol% Gamma-TiAl composites}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.msea.2013.04.092}, abstract = {Ultrafine-grained ceramic-based composites of Ti–31.6Al–21.6Si (at%) consisting of 60 vol% of ζ-Ti5Si3 and 40 vol% of γ-TiAl were produced by high-energy ball milling followed by hot isostatic pressing (HIP). Because of the cleanliness of the powder and full densification of the HIPed product, the mechanical behavior of the composite could be unambiguously related to the microstructure and chemistry. The starting microstructure after HIPing consisted of intermixed ζ-Ti5Si3 and γ-TiAl phases of approximately equal grain size, the size ranging from about 300 nm to 1 μm depending on the HIP temperature. High-temperature mechanical testing of this ultrafine-grained composite exhibited a strain-rate sensitivity of >0.3. Further, the equiaxed microstructure was retained after mechanical testing, suggesting the possibility of achieving superplastic deformation. Consequently, tensile testing demonstrated elongations of about 150% at 950 °C and a strain rate of 4×10−5 s−1. Considering that the present alloy has the ceramic (silicide) phase as the matrix, this temperature at which superplastic deformation is observed is significantly lower than that reported for conventional coarse-grained ceramic materials.}, note = {Online available at: \url{https://doi.org/10.1016/j.msea.2013.04.092} (DOI). Suryanarayana, C.; Behn, R.; Klassen, T.; Bormann, R.: Mechanical characterization of mechanically alloyed ultrafine-grained Ti5Si3+40 vol% Gamma-TiAl composites. Materials Science and Engineering A. 2013. vol. 579, 18-25. DOI: 10.1016/j.msea.2013.04.092}} @misc{alabbasi_performance_of_2013, author={Alabbasi, A., Kannan, M.B., Walter, R., Stoermer, M., Blawert, C.}, title={Performance of pulsed constant current silicate-based PEO coating on pure magnesium in simulated body fluid}, year={2013}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.matlet.2013.04.047}, abstract = {In vitro degradation behaviour of a pulsed constant current silicate-based PEO coating on pure magnesium was studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation techniques. The PEO coating increased the polarisation resistance (Rp) of magnesium by an order of magnitude and reduced the corrosion current (icorr) by 65%. EIS modelling indicated that the inner compact layer resistance of the PEO coating was critical for the overall degradation resistance of the material. However, the breakdown potential from potentiodynamic polarisation curves and the post-degradation analysis suggested that the porous outer layer of the PEO coating played an important role in the stability of the inner compact layer.}, note = {Online available at: \url{https://doi.org/10.1016/j.matlet.2013.04.047} (DOI). Alabbasi, A.; Kannan, M.; Walter, R.; Stoermer, M.; Blawert, C.: Performance of pulsed constant current silicate-based PEO coating on pure magnesium in simulated body fluid. Materials Letters. 2013. vol. 106, 18-21. DOI: 10.1016/j.matlet.2013.04.047}} @misc{pauls_gas_permeation_2012, author={Pauls, J.R., Fritsch, D., Klassen, T., Peinemann, K.-V.}, title={Gas permeation measurement under defined humidity via constant volume/variable pressure method}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.memsci.2011.10.046}, abstract = {Many industrial gas separations in which membrane processes are feasible entail high water vapour contents, as in CO2-separation from flue gas in carbon capture and storage (CCS), or in biogas/natural gas processing. Studying the effect of water vapour on gas permeability through polymeric membranes is essential for materials design and optimization of these membrane applications. In particular, for amine-based CO2 selective facilitated transport membranes, water vapour is necessary for carrier-complex formation (Matsuyama et al., 1996; Deng and Hägg, 2010; Liu et al., 2008; Shishatskiy et al., 2010) [1], [2], [3] and [4]. But also conventional polymeric membrane materials can vary their permeation behaviour due to water-induced swelling (Potreck, 2009) [5]. Here we describe a simple approach to gas permeability measurement in the presence of water vapour, in the form of a modified constant volume/variable pressure method (pressure increase method).}, note = {Online available at: \url{https://doi.org/10.1016/j.memsci.2011.10.046} (DOI). Pauls, J.; Fritsch, D.; Klassen, T.; Peinemann, K.: Gas permeation measurement under defined humidity via constant volume/variable pressure method. Journal of Membrane Science. 2012. vol. 389, 343-348. DOI: 10.1016/j.memsci.2011.10.046}} @misc{taube_reversible_wasserstoffspeicherung_2012, author={Taube, K.}, title={Reversible Wasserstoffspeicherung in Metallhydriden – Ueberblick zum aktuellen Forschungsstand}, year={2012}, howpublished = {journal article}, abstract = {No abstract}, note = {Taube, K.: Reversible Wasserstoffspeicherung in Metallhydriden – Ueberblick zum aktuellen Forschungsstand. HZwei - Das Magazin fuer Wasserstoff und Brennstoffzellen. 2012. vol. 12, no. 10, 26-28.}} @misc{bellostavoncolbe_behavior_of_2012, author={Bellosta von Colbe, J.M., Metz, O., Lozano, G.A., Pranzas, K.P., Schmitz, H.W., Beckmann, F., Schreyer, A., Klassen, T., Dornheim, M.}, title={Behavior of scaled-up sodium alanate hydrogen storage tanks during sorption}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2011.03.153}, abstract = {Sodium alanate is being experimentally tested in scaled-up quantities. For this purpose, several tanks have been designed and constructed. The tank functionality during absorption and desorption of hydrogen was demonstrated in a scale of 8 kg of alanate, with a peak technical absorption time below 10 min. The absorption and desorption data show good reproducibility. Neutron radiography was used in another tank to show the powder’s physical behavior during sorption, showing conservation of the macroscopic structure during cycling.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2011.03.153} (DOI). Bellosta von Colbe, J.; Metz, O.; Lozano, G.; Pranzas, K.; Schmitz, H.; Beckmann, F.; Schreyer, A.; Klassen, T.; Dornheim, M.: Behavior of scaled-up sodium alanate hydrogen storage tanks during sorption. International Journal of Hydrogen Energy. 2012. vol. 37, no. 3, 2807-2811. DOI: 10.1016/j.ijhydene.2011.03.153}} @misc{jepsen_economic_potential_2012, author={Jepsen, J., Bellosta von Colbe, J.M., Klassen, T., Dornheim, M.}, title={Economic potential of complex hydrides compared to conventional hydrogen storage systems}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2011.11.141}, abstract = {Novel developments of materials for solid hydrogen storage show promising prospects. Complex hydrides exhibit great technical potential to store hydrogen in an efficient and safe way. Nevertheless, so far an evaluation of economic competitiveness is still lacking. In this work, an assessment about the economic feasibility of implementing complex hydrides as hydrogen storage materials is presented. The cost structure of hydrogen storage systems based on NaAlH4 and LiBH4/MgH2 is discussed and compared with the conventional high pressure (700 bar) and liquid storage systems. The vessel construction for the complex hydride systems is much simpler than for the alternative conventional methods because of the milder pressure and temperature conditions during the storage process. According to the economical analysis, this represents the main cost advantage of the complex hydride systems.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2011.11.141} (DOI). Jepsen, J.; Bellosta von Colbe, J.; Klassen, T.; Dornheim, M.: Economic potential of complex hydrides compared to conventional hydrogen storage systems. International Journal of Hydrogen Energy. 2012. vol. 37, no. 5, 4204-4214. DOI: 10.1016/j.ijhydene.2011.11.141}} @misc{saldan_enhanced_hydrogen_2012, author={Saldan, I., Campesi, R., Zavorotynska, O., Spoto, G., Baricco, M., Arendarska, A., Taube, K., Dornheim, M.}, title={Enhanced hydrogen uptake/release in 2LiH–MgB2 composite with titanium additives}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2011.10.047}, abstract = {All the composites with the titanium additives displayed an improvement of reaction kinetics, especially during hydrogen desorption. The LiH–MgB2–TiO2 system reached a storage of about 7.6 wt % H2 in ∼1.8 h for absorption and ∼2.7 h for desorption. Using in-situ SR-PXD measurements, magnesium was detected as an intermediate phase during hydrogen desorption for all composites. In the composite with TiF4 addition the formation of new phases (TiB2 and LiF) were observed. Characteristic diffraction peaks of TiO2, TiN and TiC additives were always present during hydrogen absorption–desorption. For all as-milled composites, ATR-IR spectra did not show any signals for borohydrides, while for all hydrogenated composites B–H stretching (2450–2150 cm−1) and B–H bending (1350–1000 cm−1) bands were exactly the same as for commercial LiBH4.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2011.10.047} (DOI). Saldan, I.; Campesi, R.; Zavorotynska, O.; Spoto, G.; Baricco, M.; Arendarska, A.; Taube, K.; Dornheim, M.: Enhanced hydrogen uptake/release in 2LiH–MgB2 composite with titanium additives. International Journal of Hydrogen Energy. 2012. vol. 37, no. 2, 1604-1612. DOI: 10.1016/j.ijhydene.2011.10.047}} @misc{saldan_influence_of_2012, author={Saldan, I., Gosalawit-Utke, R., Pistidda, C., Boesenberg, U., Schulze, M., Jensen, T.R., Taube, K., Dornheim, M., Klassen, M.}, title={Influence of Stoichiometry on the Hydrogen Sorption Behavior in the LiF–MgB2 System}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp212322u}, abstract = {Chemical reactions between LiF and MgB2 with different molar ratios of 1:1 and 4:1 under hydrogen atmosphere were studied by high pressure differential scanning calorimetry (HP-DSC) and in-situ synchrotron radiation power X-ray diffraction (SR-PXD). Hydrogen sorption properties of the composites were evaluated using a Sievert’s type apparatus. After hydrogenation only LiBH4 and MgF2 are found as the main products. However, DSC characterization showed multistep events related to LiBH4 that might be explained by different phases or some intermediates.}, note = {Online available at: \url{https://doi.org/10.1021/jp212322u} (DOI). Saldan, I.; Gosalawit-Utke, R.; Pistidda, C.; Boesenberg, U.; Schulze, M.; Jensen, T.; Taube, K.; Dornheim, M.; Klassen, M.: Influence of Stoichiometry on the Hydrogen Sorption Behavior in the LiF–MgB2 System. The Journal of Physical Chemistry C. 2012. vol. 116, no. 12, 7010-7015. DOI: 10.1021/jp212322u}} @misc{suarezalcantara_3cah2__2012, author={Suarez Alcantara, K., Ramallo Lopez, J.M., Boesenberg, U., Saldan, I., Pistidda, C., Requejo, F.G., Jensen, T., Cerenius, Y., Soerby, M., Avila, J., Bellosta von Colbe, J., Taube, K., Klassen, T., Dornheim, M.}, title={3CaH2 + 4MgB2 + CaF2 Reactive Hydride Composite as a Potential Hydrogen Storage Material: Hydrogenation and Dehydrogenation Pathway}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp211620h}, abstract = {A reactive hydride composite (RHC) with initial composition 3CaH2 + 4MgB2 + CaF2 was studied by in situ synchrotron radiation powder X-ray diffraction (SR-PXD) and X-ray absorption near edge structure (XANES) at the B K-edge and at the Ca K-edge. The hydrogenation reaction proceeds by an unknown intermediate. No evidence of intermediates was observed during the dehydrogenation reaction. B and Ca K-edge XANES results hint to a closed interaction of CaF2 and Ca(BH4)2. The main function of CaF2 in the 3CaH2 + 4MgB2 + CaF2 RHC is as a dopant for the hydrogenation and dehydrogenation reactions.}, note = {Online available at: \url{https://doi.org/10.1021/jp211620h} (DOI). Suarez Alcantara, K.; Ramallo Lopez, J.; Boesenberg, U.; Saldan, I.; Pistidda, C.; Requejo, F.; Jensen, T.; Cerenius, Y.; Soerby, M.; Avila, J.; Bellosta von Colbe, J.; Taube, K.; Klassen, T.; Dornheim, M.: 3CaH2 + 4MgB2 + CaF2 Reactive Hydride Composite as a Potential Hydrogen Storage Material: Hydrogenation and Dehydrogenation Pathway. The Journal of Physical Chemistry C. 2012. vol. 116, no. 12, 7207-7212. DOI: 10.1021/jp211620h}} @misc{gaudin_amorphous_to_2012, author={Gaudin, J., Peyrusse, O., Chalupsky, J., Toufarova, M., Vysin, L., Hajkova, V., Sobierajski, R., Burian, T., Dastjani-Farahani, S., Graf, A., Amati, M., Gregoratti, L., Hau-Riege, S.P., Hoffmann, G., Juha, L., Krzywinski, J., London, R.A., Moeller, S., Sinn, H., Schorb, S., Stoermer, M., Tschentscher, T., Vorlicek, V., Vu, H., Bozek, J., Bostedt, C.}, title={Amorphous to crystalline phase transition in carbon induced by intense femtosecond x-ray free-electron laser pulses}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1103/PhysRevB.86.024103}, abstract = {rate and high atom temperature suggest a thermally activated phase transition.}, note = {Online available at: \url{https://doi.org/10.1103/PhysRevB.86.024103} (DOI). Gaudin, J.; Peyrusse, O.; Chalupsky, J.; Toufarova, M.; Vysin, L.; Hajkova, V.; Sobierajski, R.; Burian, T.; Dastjani-Farahani, S.; Graf, A.; Amati, M.; Gregoratti, L.; Hau-Riege, S.; Hoffmann, G.; Juha, L.; Krzywinski, J.; London, R.; Moeller, S.; Sinn, H.; Schorb, S.; Stoermer, M.; Tschentscher, T.; Vorlicek, V.; Vu, H.; Bozek, J.; Bostedt, C.: Amorphous to crystalline phase transition in carbon induced by intense femtosecond x-ray free-electron laser pulses. Physical Review B. 2012. vol. 86, no. 2, 024103. DOI: 10.1103/PhysRevB.86.024103}} @misc{nwakwuo_effect_of_2012, author={Nwakwuo, C.C., Eigen, N., Dornheim, M., Bormann, R.}, title={Effect of group IV elements on the thermodynamic property of NaH + Al}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.renene.2011.11.036}, abstract = {The destabilizing effect of (X) group IV elements (C, Si, Sn and Ge) on NaH + Al was investigated. A significant decrease in the desorption temperature as well as the reaction enthalpy of NaH was achieved with additions of C, Si, Ge and Sn due to the formation of NaAlGe and NaAlSi ternary and NaSn binary compounds. Compared to a reaction enthalpy of 114 kJ mol−1 H2 for NaH above 400 °C, lower reaction enthalpies of 94 kJ mol−1 H2, 72 kJ mol−1 H2, 20 kJ mol−1 H2 and 2 kJ mol−1 H2 were obtained for the NaH + Al + C, NaH + Al + Si, NaH + Al + Ge and NaH + Al + Sn mixtures with onsets at 270 °C, 220 °C, 180 °C, and 130 °C respectively. Reversible hydrogenation was partly achieved in the NaH–Al–Si system with the formation of NaAlH4 + Si.}, note = {Online available at: \url{https://doi.org/10.1016/j.renene.2011.11.036} (DOI). Nwakwuo, C.; Eigen, N.; Dornheim, M.; Bormann, R.: Effect of group IV elements on the thermodynamic property of NaH + Al. Renewable Energy. 2012. vol. 43, 172-178. DOI: 10.1016/j.renene.2011.11.036}} @misc{saldan_nexafs_study_2012, author={Saldan, I., Ramallo-Lopez, J.M., Requejo, F.G., Suarez-Alcantara, K., Bellosta von Colbe, J., Avila, J.}, title={NEXAFS study of 2LiF–MgB2 composite}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2012.04.010}, abstract = {First results of Near Edge X-ray Absorption Fine Structure (NEXAFS) at the B K-edge (193 eV) for LiF–MgB2 composite with molar ratio (2:1) are presented. Obtained results indicate a formation of mixed borohydrides/borofluorides of the type of LiBH4−xFx, thus suggesting fluorine substituting for hydrogen.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2012.04.010} (DOI). Saldan, I.; Ramallo-Lopez, J.; Requejo, F.; Suarez-Alcantara, K.; Bellosta von Colbe, J.; Avila, J.: NEXAFS study of 2LiF–MgB2 composite. International Journal of Hydrogen Energy. 2012. vol. 37, no. 13, 10236-10239. DOI: 10.1016/j.ijhydene.2012.04.010}} @misc{wolff_advances_in_2012, author={Wolff, M., Deussing, J., Dahms, M., Ebel, T., Kainer, K.U., Klassen, T.}, title={Advances in the Metal Injection Moulding of Mg-Ca alloys for biomedical applications}, year={2012}, howpublished = {journal article}, abstract = {Magnesium-Calcium alloys are attracting interest for use in biomedical applications thanks to the material’s biodegradability and its mechanical properties that closely match cortical bone. MIM processing additionally offers the ability to produce structures with both dense and porous areas. Martin Wolff and co-authors review the complete production cycle for MIM Mg-Ca alloys and present initial mechanical properties for sintered specimens.}, note = {Wolff, M.; Deussing, J.; Dahms, M.; Ebel, T.; Kainer, K.; Klassen, T.: Advances in the Metal Injection Moulding of Mg-Ca alloys for biomedical applications. Powder Injection Moulding International. 2012. vol. 6, no. 4, 59-63.}} @misc{gaudin_investigating_the_2012, author={Gaudin, J., Ozkan, C., Chalupsky, J., Bajt, S., Burian, T., Vysin, L., CoppolaN., Dastjani-Farahani, S., Chapman, H.N., Galasso, G., Hajkova, V., Harmand, M., Juha, L., Jurek, M., Loch, R.A., Moeller, S., Nagasono, M., Stoermer, M., Sinn, H., Saksl, K., Sobierajski, R., Schulz, J., Sovak, P., Toleikis, S., Tiedtke, K., Tschentscher, T., Krzywinski, J.}, title={Investigating the interaction of x-ray free electron laser radiation with grating structure}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1364/OL.37.003033}, abstract = {at the edge of the grating structure as evidenced by optical and atomic force microscopy. Simulations based on solution of the Helmholtz equation demonstrate an enhancement of the electric field intensity distribution at the edge of the grating structure. A procedure is finally deduced to evaluate damage threshold.}, note = {Online available at: \url{https://doi.org/10.1364/OL.37.003033} (DOI). Gaudin, J.; Ozkan, C.; Chalupsky, J.; Bajt, S.; Burian, T.; Vysin, L.; CoppolaN.; Dastjani-Farahani, S.; Chapman, H.; Galasso, G.; Hajkova, V.; Harmand, M.; Juha, L.; Jurek, M.; Loch, R.; Moeller, S.; Nagasono, M.; Stoermer, M.; Sinn, H.; Saksl, K.; Sobierajski, R.; Schulz, J.; Sovak, P.; Toleikis, S.; Tiedtke, K.; Tschentscher, T.; Krzywinski, J.: Investigating the interaction of x-ray free electron laser radiation with grating structure. Optics Letters. 2012. vol. 37, no. 15, 3033-3035. DOI: 10.1364/OL.37.003033}} @misc{gosalawitutke_2libh4mgh2_in_2012, author={Gosalawit-Utke, R., Nielsen, T.K., Pranzas, K., Saldan, I., Pistidda, C., Karimi, F., Laipple, D., Skibsted, J., Jensen, T.R., Klassen, T., Dornheim, M.}, title={2LiBH4MgH2 in a ResorcinolFurfural Carbon Aerogel Scaffold for Reversible Hydrogen Storage}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1021/jp2088127}, abstract = {The reactive hydride composite of 2LiBH4–MgH2 has been melt infiltrated in a resorcinol–furfural (RFF) carbon aerogel scaffold. Dried aerogel of RFF, further pyrolyzed to obtain a carbon aerogel scaffold, is prepared by CO2 supercritical drying, where time consumption is significantly lower than the normal procedures of solvent exchange and drying under ambient conditions. On the basis of scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS) mapping, the complex hydrides are homogeneously dispersed in the nanometer scale both inside the nanopores and over the surface of the RFF carbon aerogel. Synchrotron radiation powder X-ray diffraction (SR–PXD) and Raman results reveal the reaction mechanisms during melt infiltration, de- and rehydrogenation of this system, as well as the differences from the previous studies of the nanoconfined 2LiBH4–MgH2 in a resorcinol–formaldehyde (RF) carbon aerogel. Thermogravimetric and hydrogen titration measurements reveal a significant improvement in dehydrogenation kinetics of 2LiBH4–MgH2–RFF as compared with the bulk 2LiBH4–MgH2 system. For instance, an approximate single-step dehydrogenation together with almost 100% of the total hydrogen storage capacity is accomplished within 6 h during the first dehydrogenation, while the bulk material performs clearly two-step reaction and requires 30 h (at T = 45 °C and p(H2) = 3–4 bar). Moreover, the gravimetric hydrogen storage capacity in the range of 4.2–4.8 wt % (10–11.2 wt % H2 with respect to the hydride content) is maintained over four dehydrogenation and rehydrogenation cycles.}, note = {Online available at: \url{https://doi.org/10.1021/jp2088127} (DOI). Gosalawit-Utke, R.; Nielsen, T.; Pranzas, K.; Saldan, I.; Pistidda, C.; Karimi, F.; Laipple, D.; Skibsted, J.; Jensen, T.; Klassen, T.; Dornheim, M.: 2LiBH4MgH2 in a ResorcinolFurfural Carbon Aerogel Scaffold for Reversible Hydrogen Storage. The Journal of Physical Chemistry C. 2012. vol. 116, no. 1, 1526-1534. DOI: 10.1021/jp2088127}} @misc{nwakwuo_microstructural_study_2012, author={Nwakwuo, C.C., Pistidda, C., Dornheim, M., Hutchison, J.L., Sykes, J.M.}, title={Microstructural study of hydrogen desorption in 2NaBH4 + MgH2 reactive hydride composite}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2011.10.070}, abstract = {The desorption mechanism of as-milled 2NaBH4 + MgH2 was investigated by volumetric analysis, X-ray diffraction and electron microscopy. Hydrogen desorption was carried out in 0.1 bar hydrogen pressure from room temperature up to 450 °C at a heating rate of 3 °C min−1. Complete dehydrogenation was achieved in two steps releasing 7.84 wt.% hydrogen. Desorption reaction in this system is kinetically restricted and limited by the growth of MgB2 at the Mg/Na2B12H12 interface where the intermediate product phases form a barrier to diffusion. During desorption, MgB2 particles are observed to grow as plates around NaH particles.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2011.10.070} (DOI). Nwakwuo, C.; Pistidda, C.; Dornheim, M.; Hutchison, J.; Sykes, J.: Microstructural study of hydrogen desorption in 2NaBH4 + MgH2 reactive hydride composite. International Journal of Hydrogen Energy. 2012. vol. 37, no. 3, 2382-2387. DOI: 10.1016/j.ijhydene.2011.10.070}} @misc{lozano_optimization_of_2012, author={Lozano, G.A., Na Ranong, C., Bellosta von Colbe, J.M., Bormann, R., Hapke, J., Fieg, G., Klassen, T., Dornheim, M.}, title={Optimization of hydrogen storage tubular tanks based on light weight hydrides}, year={2012}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.ijhydene.2011.03.043}, abstract = {Design of hydrogen storage systems aims at minimal weight and volume while fulfilling performance criteria. In this paper, the tubular tank configuration for hydrogen storage based on light weight hydrides is optimized towards its total weight using the predictions of a newly developed simulation model. Sodium alanate is taken as model material. A clear definition of the optimization is presented, stating a new optimization criterion: a defined total mass of hydrogen has to be charged in a given time, instead of prescribing percentages of the total hydrogen storage capacity. This yields a wider space of possible solutions. The effects of material compaction, addition of expanded graphite and different tubular tank diameters were evaluated. It was found that compaction of the material is the most influential factor to optimize the storage system. In order to obtain lighter storage systems one should concentrate on improving the ratio mass of hydride bed to mass of tank wall by screening lighter materials for the tank wall and developing hydrogen storage materials exhibiting both higher gravimetric and volumetric storage capacities.}, note = {Online available at: \url{https://doi.org/10.1016/j.ijhydene.2011.03.043} (DOI). Lozano, G.; Na Ranong, C.; Bellosta von Colbe, J.; Bormann, R.; Hapke, J.; Fieg, G.; Klassen, T.; Dornheim, M.: Optimization of hydrogen storage tubular tanks based on light weight hydrides. International Journal of Hydrogen Energy. 2012. vol. 37, no. 3, 2825-2834. DOI: 10.1016/j.ijhydene.2011.03.0