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

The significantly enhanced dehydrogenation performance of binary complex system, NH3BH3/LiBH4·NH3, were achieved through a chemical modification of LiH to form ternary composites of x (LiH–NH3BH3)/LiBH4·NH3. Among the studied composites, 3LiH–3NH3BH3/LiBH4·NH3 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 3NH3BH3/LiBH4·NH3 at the same conditions. Further investigations revealed that the hydrogen emission from x (LiH–NH3BH3)/LiBH4·NH3 composites is based on the combination mechanism of Hδ+ and Hδ− through the interaction between LiH–NH3BH3 and NH3 group in LiBH4·NH3, in which the controllable protic hydrogen source from the stabilized NH3 group played a crucial role in providing optimal stoichiometric ratio of Hδ+ and Hδ−, and thus leading to the significant improvement of dehydrogenation capacity and purity.

► LiH was introduced to enhance the dehydrogenation of the NH3BH3/LiBH4·NH3 composites.
► The 3LiH–3AB/3LiBH4·NH3 composite can release 10 wt. % pure hydrogen below 100 °C
► The hydrogen release in x (LiH–AB)/LiBH4·NH3 started with the formation of LiAB.