Graphene supported cobalt(0) nanoparticles for hydrolysis of ammonia borane

Cobalt(0) nanoparticles supported on graphene have been synthesized via a one-step in situ procedure, using the mixture of ammonia borane (AB) and sodium borohydride (NaBH4) as the reducing agents under ambient temperature. Compared with NaBH4, the as-prepared Co/graphene NPs which reduced by the mixture of NaBH4/AB exhibit superior catalytic activity towards the hydrolytic dehydrogenation of AB. A kinetic study shows that the catalytic hydrolysis of AB is first order with respect to the concentration of the as as-synthesized NPs. The turnover frequency (TOF) is 13.8 mol H2 min−1 (mol Co)−1, which is higher than most of the non-noble metal catalysts, and even noble-metal based NPs. The activation energy has been measured to be 32.75 kJ mol−1, which is lower than many reported values for the catalytic hydrolytic dehydrogenation of ammonia borane.