Effects of the Preparation Solvent on the Catalytic Properties of Cobalt–Boron Alloy for the Hydrolysis of Alkaline Sodium Borohydride

In this study, the effects of the solvent used to prepare Co–B alloy on its catalytic properties were investigated. The solvent effects on the morphology, composition, and specific surface area of the alloy particles were also examined. The morphology of the alloy particles was found to be dependent on the solvent. The particles were granular in water, methanol, and acetone, although the particle diameters differed, whereas they were nanoflake-like in acetonitrile. Acetonitrile produced the largest surface area of the alloy particles, but the lowest catalytic activity for the hydrolysis of NaBH4 owing to the ready oxidation of the particles in air. The Co–B in acetone exhibited the highest catalytic activity, represented by a hydrogen generation rate of 5733 mL·min−1·g−1 during the hydrolysis of 1.5 wt % NaBH4 at 298 K. This hydrogen generation rate is more than twice that produced by the Co–B in water.