Ammonia borane destabilized by aluminium hydride: A mutual enhancement for hydrogen release

摘要

Destabilized by aluminum hydride, the dehydrogenation properties of ammonia borane (AB) can be improved significantly, including enhanced dehydrogenation kinetics, reduced induction period and suppressed formation of volatile byproducts. Furthermore, a lowered dehydrogenation temperature was also achieved for AlH_3, indicating a mutual dehydrogenation enhancement for both AB and AlH_3 in this mixture. The destabilized sample, 3AB/AlH_3,can totally release more than 12 wt% of high-pure hydrogen (＞99 wt%) without any detectable by-products below 250 ℃. Mechanism investigations indicated that the mutual dehydrogenation enhancement in the mixture is attributed to the Coulombic attraction between the hydridic H~(δ-) in AlH_3 and the protonic H~(δ+) in the NH_3 group of AB.