Cobalt-manganese-boron/nickel foam for hydrogen generation from the hydrolysis of sodium borohydride solution

Abstract

Sodium borohydride (NaBH₄) is widely favored for its own high hydrogen storage capacity. However, the H₂ release rate of NaBH₄ hydrolysis is very slow in the absence of catalysts, and so it is important to add catalysts with high performance for efficient hydrolysis. In this work, Co-Mn-B/Ni foam materials were synthesized via chemical deposition way in a mild environment and employed to catalyze NaBH₄ hydrolysis. By changing the concentration of reducing agent, the optimal Co-Mn-B/Ni foam with high catalytic performance was obtained, providing the highest H₂ generation rate of 8710 mL min⁻¹·g⁻¹ and low apparent activation energy of 34.6 kJ mol⁻¹. The catalytic performance was obviously better than that of binary Co-B/Ni foam catalyst. The improved activity of the catalyst could be attributed to the special fluffy spherical morphology of the surface, which supplied high specific surface area to efficiently transport of H₂, as well as the synergistic effect of the multiple components. In addition, the hydrogen production rate was maintained about 55.5 % of the first value after 5 cycles, showing the superior stability of Co-Mn-B/Ni foam during the hydrolysis.