Catalytic oxidation of diesel soot particulates over Pt substituted LaMn1-xPtxO3 perovskite oxides

Present paper deals with the preparation (by sol-gel method) and characterization (by H-2-TPR, XPS, XRD, IR, SEM, TEM) of the Pt substituted LaMn1-xPtxO3 (x = 0,0.05,0.1,0.2,0.3) perovskite oxides and their activities towards the diesel soot oxidation at simulated atmosphere. The results show platinum enters the perovskite crystal structure when x < 0.1. With the increase of platinum doping amount, the oxygen vacancy concentration on the catalyst surface increases, and H-2-TPR shows that the low-temperature oxidation-reduction performance of the catalyst is improved with the increase of platinum doping amount. Catalytic oxidation of soot was studied under tight contact with soot/catalyst ratio of 1/10 under a flow rate of air at 100 ml/min. LaMn0.8Pt0.2O3 perovskite catalyst was found to give the best result for soot oxidation with the light off temperatures T-10 = 339 degrees C, T-50 = 370 degrees C, T-90 = 405 degrees C. The might reaction mechanism is also presented.