Co掺杂对CuO/ CeO2-Co3O4优先氧化CO催化性能的影响

Effect of Co doping on the catalytic performance of CuO/CeO2-Co3O4 for preferential oxidation of CO

关键词:  CO优先氧化  钴  CuO-CeO₂催化剂  掺杂  共沉淀法

Key words:  CO preferential oxidation  cobalt  CuO-CeO₂ catalyst  doping  co-precipitation method

摘要:

采用共沉淀-浸渍法制备了一系列不同Ce/Co物质的量比的CeO₂-Co₃O₄载体和CuO负载量(质量分数)为7% 的CuO/CeO₂-Co₃O₄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、H₂-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/ CeO₂-Co₃O₄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CeO₂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。 

Abstract:

A series of CeO₂-Co₃O₄ supports with variable Ce/Co atomic molar ratio and the corresponding catalysts CuO/CeO₂-Co₃O₄ (CuO loading of 7 wt%) are prepared by co-precipitation and impregnation method respectively, then employed for the preferential oxidation of CO in H₂-rich stream. Techniques such as N₂-sorption, XRD, H₂-TPR were used for catalyst characterization. The catalyst CuO/CeO₂-Co₃O₄ with Ce/(Ce+Co) ratio of 0.9 exhibits the best performance. The addition of a small amount of cobalt to CuO/CeO₂ could enhance the surface area and the dispersion of copper species on the supports. A small amount of cobalt entered the CeO₂ crystal lattice, promoting the interaction between cobalt and ceria, further increases the redox properties of supports and the catalysts.