Abstract:

CoB/SiO₂ catalyst was synthesized via impregnation-chemical reduction method,and the performance of hydrolysis H₂ production from NaBH₄ catalyzed by CoB/SiO₂ catalyst was researched.The effect of factors,such as the particle size of SiO₂,the amount-of-substance ratio of cobalt nitrate to SiO₂ and the amount-of-substance ratio of cobalt nitrate to NaBH₄,on the performance of catalyst was investigated.In addition,the conditions of dosage of catalyst,stirring speed rate and reaction temperature etc.on the performance of hydrolysis H₂ production from NaBH₄ were further studied.Results showed when the particle size of SiO₂ was 15 nm,the amount-of-substance ratio of cobalt nitrate to SiO₂ was 0.08∶1,and the amount-of-substance ratio of cobalt nitrate to NaBH₄ was 1∶5,the speed rate of hydrolysis H₂ production from NaBH₄ catalyzed by CoB/SiO₂ catalyst was 45.6 mL/（min·g）.Because the particle size of the catalyst was very small,the effect of the external diffusion rate could be completely eliminated by the momentum generated in the hydrolysis H₂ production from NaBH₄.The effect of the stirring speed on the hydrolysis rate of NaBH₄ was small.The hydrolysis rate of NaBH₄ increased with the increase of the dosage of catalyst.With the increasing of the reaction temperature,the hydrolysis rate increased,the apparent activation energy of the hydrolysis reaction of NaBH₄ was 48.54 kJ/mol,and the reaction order of NaBH₄ was zero.The catalyst showed the excellent reusability and stability.

Key words: CoB/SiO₂ catalyst, NaBH₄, H₂ generation