PARTICULATE OXIDIZING MATERIAL AND OXIDATION CATALYST

摘要

A particulate oxidizing material containing a cerium-zirconium composite oxide for burning particulates in an exhaust gas from a lean burn internal combustion engine, characterized in that the cerium-zirconium composite oxide comprises cerium in a content of 0.1 to 20 mole % relative to the total moles of metal atoms contained therein. Preferably, the cerium-zirconium composite oxide further comprises at least one metal (M) selected from rare earth metals (exclusive of cerium) at a mole ratio of M/Ce of 0.1 to 10. The particulate oxidizing material enhances the rate of oxidation of particulates at a low temperature (about 300°C or lower) without interfering with the reduction or clarification of NOx at a high temperature (about 500°C or higher) due to the oxidation activity thereof at a high temperature (about 500°C or higher).