NH3BH3/LiBH4·NH3 modified by metal hydrides for advanced dehydrogenation

Abstract

Abstract The significantly enhanced dehydrogenation performance of binary complex system, NH 3 BH 3 /LiBH 4 ·NH 3 , were achieved through a chemical modification of LiH to form ternary composites of x (LiH–NH 3 BH 3 )/LiBH 4 ·NH 3 . Among the studied composites, 3LiH–3NH 3 BH 3 /LiBH 4 ·NH 3 released ca. 10 wt. % high-pure hydrogen (>99.9 mol%) below 100 °C with fast kinetics, while less than 8 wt. % hydrogen, accompanied with a fair number of volatile byproducts, were released from 3NH 3 BH 3 /LiBH 4 ·NH 3 at the same conditions. Further investigations revealed that the hydrogen emission from x (LiH–NH 3 BH 3 )/LiBH 4 ·NH 3 composites is based on the combination mechanism of H δ+ and H δ− through the interaction between LiH–NH 3 BH 3 and NH 3 group in LiBH 4 ·NH 3 , in which the controllable protic hydrogen source from the stabilized NH 3 group played a crucial role in providing optimal stoichiometric ratio of H δ+ and H δ− , and thus leading to the significant improvement of dehydrogenation capacity and purity.