Dresden 2003 – wissenschaftliches Programm
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SYCN: Computational nanoscience - from materials to biology
SYCN 102: Computational Nanoscience: From Materials to Biology (Poster, gemeinsam mit SYSE)
SYCN 102.8: Poster
Dienstag, 25. März 2003, 19:00–21:00, ZEU/160
The Structure of Magnesium Alanate — •Oliver Rubner1, Andreas Glöß2, and Reinhart Ahlrichs2 — 1Forschungszentrum Karlsruhe, Institut für Nanotechnologie, D-76133 Karlsruhe, Germany. — 2Universität Karlsruhe, Institut für Theoretische Chemie, Fritz-Haber-Weg 4, D-76131 Karlsruhe
Lately nanocrystalline MgAl2H8 has been synthesized at our institute and it seems to be a very promising representative of the well known group of alanates for use as hydrogen storage.
In our group we have been able to successfully determine the structure of the solid by ab initio calculations. This structure, consisting of layers as in CdI2, is in perfect agreement with experimental XRD data and thus we are now in the position to investigate in detail the possible mechanisms of the hydrogen abstraction. We present a model for the structural rearrangement at the phase transitions which provides insight in the stability and reversibility of the hydrogen charging/decharging process.
Recent computations on small clusters also hint at a structural rearrangement of the hydrogen atoms when the size of the crystallites is reduced. These results will be presented and discussed.
Additionally, thermodynamical and kinetic data have been calculated which support and complement preliminary experimental data.