Study on Co-B alloys for on-board hydrogen generation from sodium borohydride

Co-B precursor was prepared via a solution reaction method, and Co-B alloys were obtained by heating their precursor at various temperature. Structural characterizations showed that the precursor experienced a phase transition from an amorphous phase to crystal phases, and the corresponding BET surface area got a tendency to decrease with increasing heating temperature. XRD results indicated that at 400°C,Co-B alloy was at a mixed phase of CoB,Co and a-Co, and the mixed phase would be entirely converted into a cubic cobalt phase when temperature was more than 600°C.The Co-B alloy treated at 500°C had a major phase of high active CoB, and thus has the best catalytic activity, which can achieve a hydrogen generation rate near 3.0 L/min by per gram catalyst when accelerating the hydrolytic reaction of NaBH₄.