Au/CeO_2催化CO氧化反应行为研究  

CO catalytic oxidation over Au/CeO_2 catalysts

作　　者：李卫力[1,2] 葛庆杰[1] 徐恒泳[1] 

机构地区：[1]中国科学院大连化学物理研究所洁净能源国家实验室,辽宁大连116023 [2]中国科学院大学,北京100049

出　　处：《天然气化工—C1化学与化工》2016年第5期20-25,39,共7页Natural Gas Chemical Industry

摘　　要：通过考察不同比表面积CeO_2载体和催化剂预处理条件对Au/CeO_2催化CO氧化反应性能的影响,研究了影响Au/CeO_2催化活性的关键因素及催化剂表面氧活化行为和反应机理。结果表明,含有不同比表面积CeO_2载体的Au/CeO_2催化剂具有不同的CO氧化反应活性,其中以Au/CeO_2-89.0的催化性能最佳。O_2预处理有利于催化剂的反应性能,而H_2预处理则明显降低了催化剂的反应活性。载体CeO_2的表面晶格氧可参与Au/CeO_2表面的CO氧化反应,表面晶格氧和CO反应形成CO_2并脱附后,形成氧空位,然后气相中的O_2填补氧空位,重新形成晶格氧,形成氧化还原循环,维持反应的持续进行。The influences of CeO2 supports with different surface areas and pretreatment conditions on the CO oxidation over the Au/CeO2 catalysts were investigated experimentally. Based on which, the key factors affecting the activity of catalyst and the surface oxygen activation behavior and reaction mechanism of the catalyst were discussed. Results shows that Au/CeO2 catalysts with different CeO2 supports had different CO oxidation activities, among which Au/CeO2-89.0 exhibited the best. 02 pretreatment of Au/ CeO2 could improve its catalytic activity while H2 pretreatment evidently decrease the catalytic activity. Lattice oxygen participates in the CO oxidation on the surface of Au/CeO2. Lattice oxygen reacts with adsorbed CO to form CO2, and then oxygen vacancies form on the catalyst surface. The oxygen vacancies could react with gas phase 02 to form lattice oxygen again. Such recycling keeps the running of CO oxidation over Au/CeO2 catalyst.

关 键 词：二氧化铈 金/二氧化铈 一氧化碳氧化 预处理 脉冲反应 

分 类 号：O643.3[理学—物理化学] TQ426[理学—化学]