Calculations suggest facile hydrogen release from water using boranes and alanes as catalysts

Abstract

Producing H 2 from water is a very challenging task. Using quantum chemical calculations with the MP2 and CCSD(T) methods and the aug-cc-pVnZ basis sets (extrapolated to CBS), we investigated the possibilities of B 2H 6, AlH 3, Al 2H 6 and AlH 3BH 3 to act as catalysts in the reactions that split water. Hydrogen production from H 2O is greatly accelerated in the presence of alane, dialane or borane–alane in such a way that reaction H 2O + Al 2H 6 is a nearly spontaneous process. The main catalytic effect of AlH 3 arises from the occurrence of a strong dihydrogen bond of the type Al–H δ−– δ+H–O within a cyclic transition structure.