Co掺杂对CuO/CeO_(2)-Co_(3)O_(4)优先氧化CO催化性能的影响

Effect of Co doping on the catalytic performance of CuO/CeO_(2)-Co_(3)O_(4) for preferential oxidation of CO

采用共沉淀-浸渍法制备了一系列不同Ce/Co物质的量比的CeO_(2)-Co_(3)O_(4)载体和CuO负载量(质量分数)为7%的CuO/CeO_(2)-Co_(3)O_(4)催化剂,考察了它们在富氢气氛中对CO的优先氧化性能。采用BET、XRD、H_(2)-TPR等对催化剂进行了表征。测试结果表明:Ce/(Co+Ce)物质的量比为0.9时,CuO/CeO_(2)-Co_(3)O_(4)催化剂活性最好。少量的Co掺杂有利于提高催化剂的比表面积和铜物种在载体上的分散,少量的Co进入了CeO_(2)的晶格,增强了钴铈相互作用,进而提高了载体的氧化还原性能。

A series of CeO_(2)-Co_(3)O_(4) supports with variable Ce/Co atomic molar ratio and the corresponding catalysts CuO/CeO_(2)-Co_(3)O_(4)(CuO loading of 7 wt%)are prepared by co-precipitation and impregnation method respectively,then employed for the preferential oxidation of CO in H_(2)-rich stream.Techniques such as N 2-sorption,XRD,H 2-TPR were used for catalyst characterization.The catalyst CuO/CeO_(2)-Co_(3)O_(4) with Ce/(Ce+Co)ratio of 0.9 exhibits the best performance.The addition of a small amount of cobalt to CuO/CeO_(2) could enhance the surface area and the dispersion of copper species on the supports.A small amount of cobalt entered the CeO_(2) crystal lattice,promoting the interaction between cobalt and ceria,further increases the redox properties of supports and the catalysts.