| abstract |
(57) [Summary] [PROBLEMS] To increase the rate of particulate oxidation at a low temperature (about 300 ° C. or less), and to increase the particulate oxidation rate by the oxidation action. Provided is a particulate oxidizing material that does not hinder reduction and purification of NO x at a temperature of 00 ° C. or higher. A particulate oxidizing material containing a cerium-zirconium composite oxide for burning and purifying particulates in exhaust gas of a lean burn internal combustion engine, wherein the cerium-zirconium composite oxide contains Cerium is 0.1 to 2 based on the total number of moles of metal atoms. It is a particulate oxidizing material characterized by containing 0 mol%. Preferably, the cerium-zirconium composite oxide further contains at least one metal (M) selected from rare earth metals (excluding cerium), and M / Ce Is from 0.1 to 10. |