摘要 |
To provide a ceramic catalyst having both promoter activity and heat resistance at a small amount of promoter component and also having a low pressure drop and a low heat capacity, a noble metal as a catalyst component and at least two layers of promoter components having oxygen storage capacities are supported on a ceramic carrier which is prepared by replacing a part of component element of the ceramic material such as cordierite to enable to support a catalyst component directly thereon. The outermost layer consists of a promoter component having the highest heat resistance, and the innermost layer consists of a promoter component having the highest oxygen storage capacity, which improve heat resistance without increasing an amount of supported promoter component. |