Effect of Ce and Mn on 3DOM La0.8Sr0.2MnO3 perovskite in soot combustion under different atmospheres

Fabrication of high-performance soot combustion catalyst and clarification the reaction mechanism has been of great importance but rarely achieved. Herein, a series of three-dimensionally ordered macroporous La0.8Sr0.2MnO3 perovskite were fabricated and further decorated by Ce and Mn. The well-dispersed CeO2 on the surface of perovskite could accelerate the adsorption and activation of gaseous oxygen, therefore promoting the oxidation process. The further introduction of Mn was conclusive to the storage and utilization NOx, which was beneficial for soot combustion with the assistance of NOx. According to the catalytic performance tests and DRIFTS, CeO2-loaded catalysts tended to follow the active oxygen species derived reaction, with lowest T50 of 460 oC for C1/LSM under 5% O2/N2 atmosphere. While CeMnOx-loaded catalysts were inclined to follow the NOx-assisted catalytic reaction, and the generated nitrate species would directly participate in the reaction. The T50 of C1M2/LSM further decreased to 397 oC under 0.05% NO + 5% O2/N2 atmosphere. This work was not only devoted to design high performance catalysts for soot oxidation, but also to reveal the catalytic mechanism of these catalysts under different atmospheres.