Catalytic hydrolysis of sodium borohydride by a novel nickel–cobalt–boride catalyst

• Published in: Journal of power sources 2007-11, Vol.173 (1), p.450-457
• Main Authors: Ingersoll, J.C., Mani, N., Thenmozhiyal, J.C., Muthaiah, A.
• Format: Article
• Language: English
• Subjects: Applied sciences; Catalyst; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cell; Fuel cells; Hydrogen generation; Hydrolysis; Nickel–cobalt–boride; Sodium borohydride
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2007.04.040

With the aim of designing an efficient hydrogen generator for portable fuel cell applications nickel–cobalt–boride (Ni–Co–B) catalysts were prepared by a chemical reduction method and their catalytic hydrolysis reaction with alkaline NaBH 4 solution was studied. The performance of the catalysts prepared from NaBH 4 solution with NaOH, and without NaOH show different hydrogen generation kinetics. The rate of hydrogen generation was measured using Ni–Co–B catalyst as a function of the concentrations of NaOH and NaBH 4, as well as the reaction temperature, in the hydrolysis of alkaline NaBH 4 solution. The hydrogen generation rate increases for lower NaOH concentrations in the alkaline NaBH 4 solution and decreases after reaching a maximum at 15 wt.% of NaOH. The hydrogen generation rate is found to be constant with respect to the concentration of NaBH 4 in the alkaline NaBH 4 solution. The activation energy for hydrogen generation is found to be 62 kJ mol −1, which is comparable with that of hydrogen generation by a ruthenium catalyst.