Complete dehydrogenation of N2H4BH3 with NiM-Cr2O3 (M = Pt, Rh, and Ir) hybrid nanoparticles

Abstract

Cr₂O₃ doped NiM (M = Pt, Rh, and Ir) hybrid nanoparticles are successfully fabricated via a co-reduction route at room temperature. It is found that the addition of Cr₂O₃ not only reduces the size of the bimetallic nanoparticles and significantly increases the BET surface area as compared to that of pure Ni_0.9Pt_0.1 nanoparticles, but also increases the electron density of NiPt, resulting in significantly enhanced catalytic activity. The Ni_0.9Pt_0.1-Cr₂O₃ hybrid nanoparticles exhibit high catalytic activity for the dehydrogenation of hydrazine borane with a turnover frequency value of 1200 h⁻¹ at 50 °C, which is 20 times higher than that of pure Ni_0.9Pt_0.1 nanoparticles and even surpasses those of most of the reported heterogeneous catalysts. The catalytic performance and H₂ selectivity of NiM (M = Pt, Rh, Ir) nanoparticles are also significantly improved by the dopant Cr₂O₃. Other metal oxides MO_x (M = Mo, W and Mn) enhance the activity of the NiPt nanoparticles as well. Our study provides a general approach for the preparation of NiM/metal-oxide hybrid nanoparticles as a type of highly efficient catalyst for the complete dehydrogenation of hydrazine borane, ammonia borane and hydrazine.