Potassium?cerium?lanthanum composite oxide catalyst was prepared by citric acid complexing combustion method.The influence of reaction conditions on catalyst activity was studied by temperature programmed reaction (TPR).The optimal reaction conditions during catalytic oxidation process of soot particles were investigated and determined.The contribution of each reaction condition to catalyst activity was analyzed and compared.The results show that the increase of O2 concentration and catalyst?carbon ratio in exhaust gas are beneficial to the catalytic oxidation of soot particles.In the process of soot oxidation, the lower heating rate is more beneficial to improve the catalytic performance of the catalyst.The existence of water will partially deactivate the K?Ce?La composite oxide catalyst,which can be regenerated after drying.K?Ce?La composite oxide has good tolerance to the fluctuation of exhaust gas flow in a certain range.The contributions of reaction conditions to the catalytic activity of K?Ce?La composite oxides are as follows:catalyst?carbon ratio>contact mode>heating rate>water content>O2 concentration>tail gas flow rate.
