Ammonia borane (AB), NH3BH3, is a promising material for hydrogen storage in view of favorable gravimetric and volumetric density of hydrogen. An on-board rehydrogenation of spent material has not been demonstrated yet for AB. There are, however, ways to improve the thermodynamics of hydrogen release from AB. First, one can control the chemical nature of products of the dehydrogenation step. This approach is studied through confinement of AB in nanoporous templates. The second way to improve the thermodynamics of hydrogen release is to modify the reactant. Ammonia borane is not the only compound with the empirical formula NBH6. It was demonstrated in a series of experiments that there was another compound, diammoniate of diborane (DADB). The different properties of AB, DADB, and DBDA might be critical for hydrogen storage in the NBH materials. In particular, the thermodynamic stabilities of DADB, DBDA, and AB might be different. The properties of molecular complexes (AB)2, DADB, DBDA are characterized based on the results of electronic structure calculations. This is an abstract of a paper presented at the 230th ACS National Meeting (Washington, DC 8/28/2005-9/1/2005).
ASJC Scopus subject areas
- Chemical Engineering(all)