银掺杂调控锰铈催化剂的氧空位结构及碳烟燃烧性能OA

To enhance the catalytic combustion efficiency of diesel soot particles,the oxygen vacancy structure of Mn-Ce catalysts was modulated via silver(Ag)doping,and its effect on soot combustion performance was investigated.MnOx-CeO2 composite catalysts with different Mn-to-Ce ratios(MnxCey)were prepared using the co-precipitation method,followed by loading 3％mass percentage of Ag via impregnation.Through characterization of the physicochemical properties of the catalysts and temperature-programmed oxidation experiments,the catalytic performance for soot oxidation was analyzed.The results showed that after Ag loading,the Mn33Ce66Ag catalyst exhibited a lower ignition temperature(T10=287℃)and a lower complete combustion temperature(T90=332℃),along with excellent cyclic stability,as T90 only increased to 386℃after three cycles.Characterization analysis results show that Ag doping stabilizes Ce3+through electron injection,increases the molar ratio of surface active oxygen species,and optimizes the oxygen vacancy concentration.Through H2 temperature-programmed reduction,it is verified that Ag significantly reduces the surface oxygen reduction temperature(the main reduction peak of Mn20Ce80Ag shifted from 354.2℃to 282.2℃),accelerates oxygen activation,and enhances reducibility.The results demonstrate that the synergy between Mn4+and Ce3+promotes the activation of NO/O2,while Ag improves stability by inhibiting CeO2 grain growth and enhancing metal-support interactions.