A5048874476- Hydrogen Storage and Materials
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Boron Compounds in Chemistry
- Superconductivity in MgB2 and Alloys
- Boron and Carbon Nanomaterials Research
- Ammonia Synthesis and Nitrogen Reduction
- High-pressure geophysics and materials
- Chemical Synthesis and Characterization
- Nuclear Materials and Properties
- Hybrid Renewable Energy Systems
- Enzyme Structure and Function
- Fuel Cells and Related Materials
- Bone Tissue Engineering Materials
- 3D Printing in Biomedical Research
- Organoboron and organosilicon chemistry
- Superconducting Materials and Applications
- Thermodynamic and Structural Properties of Metals and Alloys
- Clinical practice guidelines implementation
- Inorganic Fluorides and Related Compounds
- Molecular Junctions and Nanostructures
- Solid-state spectroscopy and crystallography
- Geophysical Methods and Applications
- Advanced NMR Techniques and Applications
- Crystallography and molecular interactions
Aarhus University
2012-2021
Danish Technological Institute
2019
Aarhus School of Architecture
2017
Sodium compounds containing large weakly coordinating anions are explored as ion conductors. The halogenated sodium-closo-dodecaboranes (Na2B12Cl12, Na2B12Br12, and Na2B12I12) all isostructural (Pa3̅) at room temperature. These undergo an order–disorder polymorphic transition to Fm3̅m where Na+ partially occupies two crystallographic sites [B12X12]2– reorientational motion. dynamic structural properties promote extreme conductivity up 0.162 S/cm elevated temperature (500 °C). temperatures...
Abstract Silver compounds share a rich history in technical applications including photography, catalysis, photocatalysis, cloud seeding and as antimicrobial agents. Here we present class of silver (Ag 2 B 10 H Ag 12 ) that are semiconductors with bandgap at 2.3 eV the green visible light spectrum. The boranes have extremely high ion conductivity dynamic-anion facilitated + migration is suggested based on structural model. enhanced more than two orders magnitude room temperature (up to 3.2...
New sample environments and techniques specifically designed for in situ powder X-ray diffraction studies up to 1000 bar (1 = 10 5 Pa) gas pressure are reported discussed. The cells can be utilized multiple purposes a range of research fields. Specifically, investigations gas–solid reactions handling under inert conditions undertaken here. Sample containers allowing the introduction from one or both ends considered, enabling possibility flow-through studies. Various containment materials...
A detailed investigation of the decomposition reactions and decay in hydrogen storage capacity during repeated release uptake cycles for reactive composite LiBH4–Al (2:3) is presented. Furthermore, influence a titanium boride, TiB2, additive investigated. The study combines information from multiple techniques: situ synchrotron radiation powder X-ray diffraction, Sieverts measurements, simultaneous thermogravimetric analysis, differential scanning calorimetry mass spectroscopy, solid-state...
Eutectic melting, reactive hydride composites, and nanoconfinement have the potential to improve reversible hydrogen storage properties in metal borohydrides. We study compare combined effect of all three methods on release uptake eutectic melting lithium potassium borohydride system, 0.725LiBH4–0.275KBH4, with low temperature (Tm = 105 °C). The mixture composites Mg or MgH2 are melt infiltrated into a CO2 activated nanoporous carbon scaffold, their compared those bulk samples. decomposition...
Abstract X‐ray diffraction is a superior technique for structural characterization of crystalline matter. Here we review the use in situ powder (PXD) mainly real‐time studies solid‐gas reactions, data analysis and extraction valuable knowledge structural, chemical physical properties. Furthermore, may also provide on reaction mechanisms, kinetics thermodynamic Thus, PXD simultaneously provides properties as function pressure, temperature and/or time at different length scales, i.e. nanoscale...
Numerous intermediates are involved in the decomposition mechanism of LiBH<sub>4</sub>–MgH<sub>2</sub>–Al and cyclic stability is evaluated.
The hydrogen absorption properties of metal closo-borate/metal hydride composites, M2B10H10-8MH and M2B12H12-10MH, M = Li or Na, are studied under high pressures to understand the formation mechanism borohydrides. storage composites have been investigated by in situ synchrotron radiation powder X-ray diffraction at p(H2) 400 bar ex measurements 526 998 bar. experiments reveal crystalline intermediates before borohydrides (MBH4) formed. On contrary, M2B12H12-10MH (M Na) systems show no...
This work presents the structural and thermal properties of ammine metal dodecahydro-<italic>closo</italic>-dodecaboranes their reversible ammonia (or hydrogen) storage.
Metal closo-boranes show remarkable thermal and chemical stabilities, making them appealing candidates for a wide range of applications, such as electrolytes in electrochemical batteries ammonia storage indirect hydrogen storage. Furthermore, owing to the large size nonspherical geometry anion (e.g., B10H102– or B12H122–), metal display rich structural diversity polymorphism. Here, we present synthesis, characterization, determination ammoniated closo-boranes, Na2B10H10·nNH3 (n = 1, 2). The...
We present a molecular dynamics study of the low-temperature polymorph silver closo-borate α-Ag2B12H12, which is promising ionic conductor. By means 1H and 11B nuclear magnetic resonance spectroscopy, we identified two dynamic processes in system that involve movements B12H122– cages: fast rotations with an activation energy 308 meV tumbling cages at lower temperatures 67 meV. Fast are known to facilitate diffusion Ag+ ions (the 482 for ion jumps was determined from solid-state conductivity...
We investigated molecular dynamics in two ammonium borane systems from the group of promising ion conductors. The investigation was performed by means 1H and 11B NMR spectroscopy spin–lattice relaxation techniques. identified reorientational processes, rotations NH4 units that are present already at low temperatures large boron cages, B10H10 or B12H12, which thermally activated become prominent above 250 K. Activation energies for these processes were determined. In addition, solid-state...
Density functional B3LYP calculations of the electric field gradient at metal site in small linear cadmium model complexes and two larger structures are presented. The results compared to those by Hartree−Fock, second-order Møller−Plesset, experiment. quality basis set is tested augmenting uncontracted Kellö Sadlej with additional functions. generally gives an which smaller magnitude than Hartree−Fock a reduction range 0.1−1.4 atomic units (au) or 15−30% for examined complexes. This seems be...
Assessment of metal closo -borane photoluminescence.
Abstract Review: 126 refs.