负载型Ni-Co-P/CNFs催化剂的制备及释氢性能

以纳米碳纤维(CNFs)为基体材料,采用化学镀法在CNFs表面沉积了Ni-Co-P催化剂。研究了催化剂用量,硼氢化钠、氢氧化钠浓度,温度等对碱性硼氢化钠溶液水解释氢的影响。电感耦合等离子体原子发射光谱法(ICP-AES)测试得出负载型Ni-Co-P催化剂含镍13.30%(质量分数,下同)、钴82.25%、磷4.45%。硼氢化钠水解释氢实验结果表明,产氢速率与催化剂用量呈线性关系。当温度为45 ℃、催化剂浓度为7.5 g/L、氢氧化钠浓度为5%、硼氢化钠浓度为2.5%时,氢气释放速率达到最大值18.044 L/(g·min)。通过对负载型催化剂Ni-Co-P/CNFs催化碱性硼氢化钠溶液释放氢气动力学研究表明,该催化剂的活化能E_a为51.57 kJ/mol。

Hydrogen generation from the hydrolysis of sodium borohydride solution over the supported Ni-Co-P/CNFs catalysts

The Ni-Co-P catalysts supported on carbon nanofibers (CNFs) were prepared via electroless deposition; the mass fractions of nickel, cobalt and phosphorus in Ni-Co-P layer are 13.30%, 82.25% and 4.45%, respectively, as determined by ICP-AES. The effects of catalyst amount, sodium borohydride and sodium hydroxide concentrations and reaction temperature on the rate of hydrogen generation in the hydrolysis of alkaline NaBH₄ solution were investigated. The results indicated that the rate of hydrogen generation is proportional to the used catalyst amount; a maximum hydrogen generation rate of 18.044 L/(g·min) is achieved at 45 ℃ by hydrolysis of 2.5% NaBH₄ solution containing 5% NaOH and 7.5 g/L Ni-Co-P/CNFs catalyst with a Ni-Co-P loading of 18.127%. Moreover, a kinetic study shows that the activation energy for the hydrolysis of alkaline NaBH₄ solution under those conditions is 51.57 kJ/mol.