<i>In situ</i> Synthesis of Reduced Graphene Oxide Supported CoMo Nanoparticles as Efficient Catalysts for Hydrogen Generation from NH₃BH₃

Abstract

Abstract CoMo nanoparticles (NPs) supported on reduced graphene oxide (RGO) were synthesized by a one-step in situ co-reduction of an aqueous solution of cobalt(II) chloride, sodium molybdate dihydrate and graphene oxide (GO) using NaBH 4 as the sole reductant under ambient conditions. The powder XRD, FTIR, EDS and TEM were employed to characterize the structure, size and composition of the CoMo/RGO catalysts. The as-synthesized Co 0.9 Mo 0.1 /RGO catalysts exhibited high catalytic activity for the hydrolytic dehydrogenation of ammonia borane (AB) at room temperature. The as-synthesized Co 0.9 Mo 0.1 /RGO nanocatalysts exhibited much higher catalytic activity than Co/RGO, Mo/RGO and the RGO-free Co 0.9 Mo 0.1 counterpart. Moreover, kinetic studies indicate that the catalytic hydrolysis of AB by Co 0.9 Mo 0.1 /RGO has first order kinetics with respect to the the catalyst concentration, but zero order kinetics with respect to the substrate concentration. The Co 0.9 Mo 0.1 /RGO catalyst has a turnover frequency (TOF) of 15.8 mol H 2 ·(mol·Co 0.9 Mo 0.1 /RGO) −1 ·min −1 at 25°C. Furthermore, the Co 0.9 Mo 0.1 /RGO show good recyclability for hydrogen generation from an aqueous solution of AB, which enables the practical reuse of the catalysts. Hence, this general method can be easily extended to the facile preparation of other RGO-based metallic systems.