Carbon-supported Ni sub(3)B nanoparticles as catalysts for hydrogen generation from hydrolysis of ammonia borane

We report the preparation of Ni sub(3)B and carbon-supported Ni sub(3)B (denoted as Ni sub(3)B/C) nanoparticles, and their catalytic performance for hydrogen generation from hydrolytic dehydrogenation of ammonia borane (NH sub(3)BH sub(3), AB). Ni sub(3)B and Ni sub(3)B/C were prepared via a chemical reduction and crystallization in tetraethylene glycol solution. The obtained Ni sub(3)B catalysts are in well-defined crystalline state and Ni sub(3)B/C catalysts have a high dispersion in the carbon. The hydrogen generation measurement shows that the carbon-supported Ni sub(3)B presents enhanced catalyst activity during hydrolytic dehydrogenation of AB. Among the as-prepared Ni sub(3)B/C catalysts, Ni sub(3)B/C with 34.25 wt% Ni sub(3)B loading displays the best catalytic activity, delivering a high hydrogen release rate of 1168 mL min super(-1) g super(-1) and the lower activation energy of 46.27 kJ mol super(-1). The kinetic results show that the hydrolysis is a first-order reaction in catalyst concentration, while it is a zero-order in AB concentration. Furthermore, the Ni sub(3)B/C is a recyclable catalyst under mild reaction conditions, indicating that the carbon-supported Ni sub(3)B is a promising catalyst for AB hydrolytic dehydrogenation.