负载型 Ni－Co－P／CNFs 催化剂的制备及释氢性能

摘要

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 are13 .30%, 82.25% and 4.45%, respectively , as det ermined by ICP-AES.The effec ts of catalyst amoun t, sodium borohydride and sodium hydroxide concentrations and reaction tem perature on the rate of hydrogen generationi n theh ydro lysis of alkaline NaBH4 solutio n we re 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 ℃b y hydrolysis of 2.5% NaBH4 solution cont aining 5% NaOH and 7.5 g/L Ni-Co-P/CNFs catalyst with a Ni-Co-P loadin g of 18.127%.Moreov er, a kinetic study shows that the activation energy for the hydr olysis of alkaline NaBH4 solution under those conditions is 51.57 kJ/mol.%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 Ea 为51．57 kJ／mol。