| 摘要 |
PURPOSE:To enhance the catalyst performance within a wide temp. range by using the fine powder of a perovskite multiple oxide and the oxidizing catalyst consisting of precious metal particles in a catalyst layer of an exhaust gas purification catalyst body. CONSTITUTION:A catalyst layer 2 is formed on the surface of a ceramic structure 1 having an air outlet hole through which exhaust gases are passed and which constitutes the backbone of an exhaust gas purification catalyst. This catalyst layer 2 consists of a ceramic fiber 3, fine ceramic powder 4, an oxidizing catalyst 5 and an inorg. binder 6, and the oxidizing catalyst 5 consists of the fine powder 5a of perovskite multiple oxide and the precious metal particles 5b of at least any one of platinum, palladium and rhodium. The ceramic fiber 3, the fine ceramic powder 4, the oxidizing catalyst 5 and the inorg. binder 6 are throughly mixed and water is added to this mixture to prepare a mixed slurry adjusted to a suitable viscosity. The ceramic structure 1 is sprayed with the mixed slurry or immersed therein to coat its surface therewith, followed by drying. This coat is then calcined to obtain the catalyst layer 2. |
