CoB/Al_2O_3非晶态合金催化剂的制备及在催化制氢中的应用

Preparation of Al_2O_3 supported Co B amorphous alloy catalyst and its application in hydrogen generation

通过浸渍与化学还原相结合的方法制备了活性三氧化二铝负载Co B非晶态合金的负载型催化剂,并把该催化剂应用于硼氢化钠水解制氢反应。用SEM、XRD及BET等对三氧化二铝负载Co B非晶态合金催化剂的微观结构进行了系统表征,结果表明,非晶态合金Co B纳米颗粒能够均匀地分布于三氧化二铝表面,抑制了磁性纳米粒子Co B的团聚现象,显著提高活性组分Co B的分散度。产氢实验表明,具有高比表面积的负载型催化剂显著提高了硼氢化钠水解产氢速率,经计算硼氢化钠催化水解反应活化能约为55.21 k J/mol,明显低于基于非负载型Co B催化剂硼氢化钠催化水解反应的活化能(73.37 k J/mol)。同时随着温度、负载量及催化剂用量的增加,产氢速率也随之增加,25℃时水解反应的产氢速率约为1.03 m L/(min·mol)。

Activated A12O3 supported CoB amorphous alloy （CoB/A12O3）catalysts were prepared via a combined impregnation and chemical reduction method,which was applied in hydrogen generation from sodium borohydride hydrolysis.The mi- erostructure of CoB/AI：O3 catalyst was systematically characterized by SEM, XRD, and BET etc..Results indicated that CoB amorphous alloys were well distributed onto A12O3 surface, which effectively inhibited the agglomeration of magnetic CoB nanoparticles and improved the CoB dispersion.h was found that CoB/A12O3 catalyst with high specific surface area enhanced the hydrogen generation and its calculated activation energy was approximately 55.21 kJ/mol.The activation energy was sig- nificantly lower than unsupported CoB catalyst（73.37 kJ/mol）.Moreover, the hydrogen production rate increased with the in- creasing reaction temperature, catalyst loading ratio, and catalyst dosage.The supported catalysts could achieve high hydrogen generation rate up to 1.03 mL/（min-mol） at 25 ℃.