Rare earth metal modified three dimensionally ordered macroporous MnO_x-CeO_2 catalyst for diesel soot combustion  

作　　者：qing tang jun du bin xie yu yang wenchong yu changyuan tao 

机构地区：[1]laboratory of green chemistry and chemical,college of chemistry and chemical engineering,chongqing university,Chongqing 400030，China

出　　处：《Journal of Rare Earths》2018年第1期64-71,共8页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(21006130,51274261)

摘　　要：Three dimensionally ordered macroporous （3DOM） Ce-based catalysts were successfully prepared via a surfactant-assisted colloidal crystal template （CCT） route. The as-synthesized catalysts showed well- ordered structures with macropores and small interconnected pore windows. The Raman results indi- cate that the catalyst persists pure fluorite cubic phases until the molar ratio of Mn exceeds O.3, therefore MnOx particles form and impede the contact of the active site and the reagent and restraining soot combustion. The doping of Nd into MnOx-CeO2 enhances the catalytic activity because of increased oxygen vacancy, Mn4- content and stronger redox ability. Nd-doping also improves thermal stability of the catalyst due to less sintering and none phase separation after thermal aging. The flesh and aged Mno.3Ceo.6Ndo.lO2 catalysts show the maximum oxidation rate for soot at 331 and 355 ℃in the O2/N2 atmosphere, achieving a nearly 100% CO2 selectivity.Three dimensionally ordered macroporous （3DOM） Ce-based catalysts were successfully prepared via a surfactant-assisted colloidal crystal template （CCT） route. The as-synthesized catalysts showed well- ordered structures with macropores and small interconnected pore windows. The Raman results indi- cate that the catalyst persists pure fluorite cubic phases until the molar ratio of Mn exceeds O.3, therefore MnOx particles form and impede the contact of the active site and the reagent and restraining soot combustion. The doping of Nd into MnOx-CeO2 enhances the catalytic activity because of increased oxygen vacancy, Mn4- content and stronger redox ability. Nd-doping also improves thermal stability of the catalyst due to less sintering and none phase separation after thermal aging. The flesh and aged Mno.3Ceo.6Ndo.lO2 catalysts show the maximum oxidation rate for soot at 331 and 355 ℃in the O2/N2 atmosphere, achieving a nearly 100% CO2 selectivity.

关 键 词：Neodymium dopingMnOx-CeO2Oxygen vacanciesSoot combustionThermal aging performanceThree dimensionally ordered macroporousstructure 

分 类 号：TF2[冶金工程]