Abstract:

For the deep removal of CO from hydrogen-rich gas,the preparation of catalysts with better CO-Prox catalytic performance is a current research hotspot.CuO/NiO-CeO₂ catalysts were prepared by stepwise impregnation method,and the catalysts were characterized by XRD,BET,H₂-TPR and HR-TEM to investigate the effects of molar loading of metal Cu+Ni (metal loading) on the catalysts' structure,reduction properties and their CO-Prox performance.The results showed that Cu/Ni-O-Ce solid solutions were all formed in CuO/NiO-CeO₂ catalysts.The catalytic activity is mainly related to the content of Cu species highly dispersed on the carrier surface as well as to the content of the solid solution.Among them,the catalyst with a metal loading of 8% had a higher content of Cu species highly dispersed on the carrier surface and a higher content of solid solutions,and the catalyst exhibited better catalytic activity.Under the CO/H₂/CO₂/O₂/Ar atmosphere,a reaction temperature of 130 °C,an oxygen excess coefficient of 1.2,and a mass-air velocity of 20 266 mL/（g·h）,the CO conversion was 95.9%,and the CO oxidation selectivity was 86.3%.

Key words: Metal loading, CuO/NiO-CeO₂, CO-Prox catalytic performance, Highly dispersed Cu species, Solid solution

摘要：

为深度去除富氢气中的CO，制备CO-Prox催化性能较好的催化剂是目前的研究热点。采用分步浸渍法制备了CuO/NiO-CeO₂催化剂，通过XRD、BET、H₂-TPR、HR-TEM等手段对催化剂进行表征，探究了金属Cu+Ni的负载量（金属负载量）对催化剂结构、还原性能及其CO-Prox性能的影响。结果表明，CuO/NiO-CeO₂催化剂中均形成了Cu/Ni-O-Ce固溶体；催化活性主要与高度分散在载体表面的Cu物种和固溶体的浓度有关；当金属负载量为8%时，高度分散在载体表面的Cu物种和固溶体的浓度较高，催化剂表现出较好的催化活性；在CO/H₂/CO₂/O₂/Ar气氛下、反应温度为130 ℃、氧过量系数为1.2、质量空速为20 266 mL/（g·h）的条件下，CO转化率为95.9%，CO氧化选择性为86.3%。

关键词: 金属负载量, CuO/NiO-CeO₂, CO-Prox催化性能, 高分散Cu物种, 固溶体