Abstract:

Hydrogen production by hydrolysis of sodium borohydride by means of metal catalyst is a practical，environment-friendly and feasible approach. Especially，using the solid state sodium borohydride or its mixture directly is simpler and safer than using its solution. The present work was focused on the design of a small scale generator suitable for H₂ generation from the mixture powders of sodium borohydride and cobalt acetate as catalyst precursor at a reasonable temperature and at high generation efficiency. The initial temperature，flow rate of water，mixture ratio and product composition were investigated experimentally. It was found that the process temperature measured directly by a thermocouple fluctuated in a small range of 6～8 ℃，which could decrease the peak value of H₂ generation rate and obtain a steady hydrogen flow. A high H₂ generation efficiency > 95% was achieved under the mixture ratio with the catalyst being more than 4%. The catalyst cobalt acetate was formed in-situ and evenly distributed.