Cobalt oxide catalyst for hydrolysis of sodium borohydride and ammonia borane

The catalytic properties of Co3O4 in NaBH4 and NH3BH3 hydrolysis have been studied. Experiments were carried out at 20-40 degrees C using 0.12 M hydride solution. According to magnetic susceptibility measurements, FTIR, XRD, and TEM studies, Co3O4 is reduced to the ferromagnetic catalytically active Co2B phase under the action of the NaBH4 hydrolysis reaction medium. A correlation was found between the content of the cobalt boride phase formed in situ and catalyst activity. The reduction of Co3O4 in NH3BH3 proceeds at slower rate than in NaBH4. The addition to a solution of NH3BH3 of even a small amount of NaBH4 increases considerably the reduction rate of Co3O4. Using a Co3O4-based precursor instead of the widely used CoCl2 leads to the formation of a stable catalytically active phase of cobalt boride. (C) 2010 Elsevier B.V. All rights reserved.