| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compound oxide having an improved catalyst performance after exposed to high temperature by using three components comprising alumina, ceria and zirconia and increasing the content of the zirconia on the basis of the ceria. SOLUTION: This compound oxide comprises the three components of alumina, ceria and zirconia. The ceria and the zirconia are contained in a weight ratio of 1/(>1 to 3). The weight ratio of the alumina to the total amount of the ceria and the zirconia is preferably 1/(1-4). The compound oxide is obtained by stirring and dissolving an alumina compound, cerium nitrate and zirconium nitrate in pure water, dropping the obtained mixture solution into an ammonia aqueous solution with agitation until to reach a pH of 9-9.5, and subsequently aging the produced precipitates. It is desirable that the mixture solution has an oxide concentration of 10-100 g/L. |
