| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a combustion catalyst exhibiting satisfactory purification performance and having a long life. SOLUTION: The surface of a carrier, through which the mixed gas of fuel and air is passed, is coated with a coating material. Catalysts 2, 3 are produced by dispersing a catalytically active substance in the coating material. The combustion catalyst is constituted by arranging the catalysts 2, 3 upstream and downstream of the flow of the mixed gas. In this case, the coating material of the catalyst 3 in the downstream part is constituted of such coating material that both the phase of the coating material of the catalyst 2 in the upstream part and a stable phase having a specific surface area smaller than that of this phase are mixed. Thereby, a stable phase having a small specific surface area is mixed in the catalyst 3 in the downstream part. Accordingly, the phase transition of the coating material of the catalyst in the underflow part at a high temperature is prevented and the life of the catalyst is prolonged.</p> |
