Three dimensionally ordered macroporous(3 DOM) Ce-based catalysts were successfully prepared via a surfactant-assisted colloidal crystal template(CCT) route. The as-synthesized catalysts showed wellordered structures with macropores and small interconnected pore windows. The Raman results indicate that the catalyst persists pure fluorite cubic phases until the molar ratio of Mn exceeds 0.3, therefore MnO_x particles form and impede the contact of the active site and the reagent and restraining soot combustion. The doping of Nd into MnO_x-CeO_2 enhances the catalytic activity because of increased oxygen vacancy, Mn^(4+)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 fresh and aged Mn_(0.3)Ce_(0.6)Nd_(0.1)O_2 catalysts show the maximum oxidation rate for soot at 331 and 355 ℃ in the O_2/N_2 atmosphere, achieving a nearly 100% CO_2 selectivity.
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