COMPLEX OXIDE METHOD FOR PRODUCING SAME AND EXHAUST GAS PURIFYING CATALYST

摘要

A cerium-containing cerium composite oxide having excellent heat resistance and excellent reduction ratio that can maintain a high specific surface area even when used in a high temperature environment, a process for producing the same, and a catalyst for purification of exhaust gas using the same. The composite oxide of the present invention contains silicon in an amount of 2 to 20 mass% in terms of SiO ₂ , and has a specific surface area of not less than 40 m ² / g by the BET method after firing at 1000 ° C. for 5 hours, The reduction ratio calculated from the results of the temperature raising and reducing measurement from 50 캜 to 900 캜 is 30% or more, and is particularly suitable as a promoter of a catalyst for purification of exhaust gas used in automobiles and the like.