Hydrogen release from aqueous hydrazine bisborane

Aqueous hydrazine bisborane H3BN2H4BH3 (HBB) might be a possible liquid-state chemical H storage material at the conditions that the compound totally dehydrogenates in mild conditions. Herein we demonstrate such a potential. We report for the first time a work about the dehydrogenation of aqueous HBB. The compound is not stable in water. Its stability is even lower in alkaline conditions because of the likely formation of the unstable intermediate [H3BOH]−. The use of a metal-based catalyst accelerates the hydrolysis of the BH3 groups but the bimetallic NiPt catalyst is more active, being also able to decompose the N2H4 moiety. The best kinetics is observed at 70 °C and in alkaline conditions. However, the dehydrogenation is not total, reaching a limit of 80% of conversion. Unfortunately the reason of that is not understood yet. As things stand, there are some challenges ahead, but HBB has shown to be a possible liquid-state chemical H storage material.