Ni–Fe–B catalysts for NaBH4 hydrolysis

A series of Ni–Fe–B catalysts with different Fe/(Fe+Ni) molar ratios, used for the hydrolysis of NaBH4, were prepared by chemical reduction of NiCl2 and FeCl3 mixed solution with NaBH4. The measurements revealed that the catalysts with the molar ratio of Fe/(Fe+Ni) (30%) exhibited the highest catalytic activity, and the optimal reduction temperature is 348K. In addition, the effects of the concentration of NaBH4, NaOH and the hydrolytic temperature of NaBH4 were discussed in detail. The results show that the reaction rate of hydrolysis first rises up and then goes down subsequently with the increase of NaBH4 concentration, as well as the concentration of NaOH. The activation energy of the hydrolysis for Ni–Fe–B catalysts is fitted to 57kJ/mol. The maximum value of hydrogen generation is 2910ml/(ming) at 298K. ► Small amount of doped-Fe has a positive effect. ► Ni–Fe–B catalysts with Fe/(Fe+Ni) molar ratio equaling to 30% show the best activity. ► Catalysts prepared at 348K perform better than that at lower temperature.