Ce基复合氧化物同时催化去除碳烟-NO_x的性能研究  

Ce-based Catalysts for Simultaneous Removal of Both Diesel Soot and NO_x

作　　者：王舒捷[1] 邹谷初[1] 徐尧[1] 陈铭夏[1] 上官文峰[1] 永长久宽 寺冈靖刚 

机构地区：[1]上海交通大学机械与动力学院燃烧与环境技术中心,上海200240 [2]日本九州大学综合理工学府

出　　处：《分子催化》2015年第1期60-67,共8页Journal of Molecular Catalysis(China)

基　　金：国家自然科学基金(20807027)

摘　　要：我们采用柠檬酸配合法制备了Ce基复合氧化物催化剂,分别在热重分析仪(TG)和管式反应器中测试了其氧化碳烟及同时脱除NOx的催化活性;并利用XRD、BET、H2-TPR、XPS表征手段考察其结构.其中,Co0.1/C e La0.05复合氧化物同时催化去除碳烟和NOx的性能最佳,碳烟脱除率为50%的反应温度为301℃,N2产率为41.4%.实验结果表明,Co主要以氧化物形式均匀分散在Ce-La固溶体表面,Co3+与Co2+价态共存,离子间的变价有利于提高催化剂的氧化还原性能,有效降低了碳烟的起燃温度.La的引入增大了催化剂的比表面积,抑制了Ce O2晶粒长大,进而提高了N2产率.部分La和Co形成了微量的La Co O3,形成了更多氧空位,有利于提高催化氧化碳烟的活性.Ce-based oxides were prepared by citric acid complex method and characterized by nitrogen physisorption,XRD,BET,H2-TPR and XPS; their catalytic performances in simultaneous removal of diesel soot and NOx were investigated on a thermogravimetric apparatus and a tubular reactor. Co0. 1/ Ce La0. 05 prevailed over all the detected materials in catalytic performance for simultaneous removal of soot and NOx. T50 of this catalyst( temperature for 50% soot combustion) was 301 ℃,and the yield of N2 was 41. 4%. A majority of cobalt oxides were dispersed on the surface of Ce-La solid solution. The mutual transformation between Co3 +and Co2 +enhanced the redox ability and oxygen storage capacity of pure ceria oxide,achieving lower temperature of combustion. Cerium-cobalt complex oxide doped with lanthanum presented a tremendous increase of surface area,leading to higher yield of N2. The f ormation of trace amount of La Co O3 promoted oxygen vacancies creation,thus affecting positively to the soot combustion activity.

关 键 词：催化去除 铈基氧化物 碳烟 NOx 柠檬酸配合法 

分 类 号：O643.32[理学—物理化学] X701[理学—化学]