Ultrafine Ni-Pt Alloy Nanoparticles Grown on Graphene as Highly Efficient Catalyst for Complete Hydrogen Generation from Hydrazine Borane

Ultrafine Ni-Pt alloy NPs grown on graphene (NiPt/graphene) have been facilely prepared via a simple one-step coreduction synthetic route and characterized by transmission electron microscopy, energy-dispresive X-ray spectroscopy, X-ray diffraction, inductively coupled plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy, Raman and Fourier transform infrared methods. The characterized results showed that ultrafine Ni-Pt NPs with a small size of around 2.3 nm were monodispersed on the graphene nanosheet. Compared to the pure Ni0.9Pt0.1, alloy NPs, graphene supported Ni0.9Pt0.1 alloy NPs exhibited much higher activity and hydrogen selectivity (100%) toward conversion of hydrazine borane (HB) to hydrogen. It is first found that the durability of the catalyst can be greatly enhanced by the addition of an excess amount of NaOH in this reaction, because of the neutralization of NaOH by the byproduct H3BO3 produced from the hydrolysis of HB. After six cycles of the catalytic reaction, no appreciable decrease in activity was observed, indicating that the Ni0.9Pt0.1/graphene catalysts have good durability/stability.