分子筛USY负载硼化钴非晶态合金催化剂的制备及其在催化硼氢化钠水解制氢中的应用

采用浸渍法与化学还原法相结合制备了一系列USY型分子筛负载非晶态合金硼化钴(CoB/USY)催化剂,并系统探究了该催化剂在催化硼氢化钠水解制氢中的催化活性。 XRD表征表明,USY分子筛载体上负载的活性组分CoB属于非晶态结构。 通过扫描电子显微镜,对比了负载型CoB/USY催化剂和粉末状CoB催化剂的微观形貌,发现非晶态合金活性组分CoB能够很好的分布在USY分子筛载体表面,较粉末状CoB有更高的分散度。 催化硼氢化钠水解制氢实验结果表明,相对于粉末状CoB催化剂,负载型CoB/USY催化剂在硼氢化钠水解制氢中具有更高的催化活性,30 ℃时NaBH₄水解产氢速率约为1.5 L/(min·g)。 反应动力学的计算结果显示,负载型CoB/USY催化剂在催化NaBH₄水解制氢反应中表观活化能约为65.9 kJ/mol,大大低于粉末状CoB催化剂的活化能(72.1 kJ/mol)。

Preparation of USY Zeolite Supported Cobalt Boride Amorphous Alloy Catalysts and Its Application in Catalytic Hydrogen Production via Hydrolysis of Sodium Borohydride

USY zeolite supported cobalt boride amorphous alloy catalysts(CoB/USY) were prepared via a combined impregnation and chemical reduction method. Their catalytic activities were investigated in hydrogen production from the hydrolysis of NaBH₄. XRD characterization indicates that CoB active components supported by USY zeolite have excellent amorphous structure. Micro-morphology of CoB/USY supported catalysts and powdered CoB were checked using SEM. SEM images show that the amorphous CoB are well dispersed onto USY surface which brings relatively high dispersions of CoB species. In the hydrogen generation from NaBH₄ hydrolysis, CoB/USY supported catalyst exhibits much higher catalytic activity compared with powdered CoB catalyst. The hydrogen generation rate of CoB/USY supported catalysts reaches about 1.5 L/(min·g), when the temperature is 30 ℃. The calculated apparent activation energy for NaBH₄ hydrolysis is 65.9 kJ/mol based on CoB/USY supported catalysts which is obviously lower than that of powdered CoB catalyst(72.1 kJ/mol).