Mg modified MnOx-CeO2-δ catalyst for low temperature complete oxidation of simulated diesel engine exhaust

Abstract

The series of Mg doped MnOxCeO2-δ were prepared by co-precipitation and investigated for complete oxidation of propene, CO and simulated diesel engine exhaust. The optimized MgO-MnOxCeO2-δ catalyst showed higher CO conversion at lower temperature (<65 °C) compared to the MnOxCeO2-δ and 1 wt% Pt/Al2O3. The MgO-MnOxCeO2-δ catalyst also showed higher activity at lower temperature under the simulated diesel engine exhaust. The catalysts were characterized by PXRD, N2 adsorption, ICP-AES, EDS, H2-TPR, XPS, O2-TPD, Raman, HRTEM techniques. The characterizations revealed the formation of MgO nanorods. MgO could be responsible for the increase in distortion of Ce lattice by forming oxygen vacancies. The Mg doped MnOxCeO2-δ catalyst showed a smaller size of Mn2O3 nanorods and increase in concentration of surface oxygen compared to the MnOxCeO2-δ catalyst. A well-dispersed MgO could be responsible for the abstraction of the proton by lowering the activation energy which resulting in the facile activation of the hydrocarbon.