| 摘要 |
PURPOSE:To increase the warming up effect in the monolith catalyst for purifying exhaust gas by increasing the carrying quantity of ceria in the downstream side in the stream of exhaust gas in a supporting body of the catalyst compared to that in the upstream side and increasing the carrying quantity of catalytic noble metal components in the downstream side compared to that in the upstream side. CONSTITUTION:A carrying layer at least contg. alumina is formed on a supporting body of a monolith catalyst having a columnar shape and having many fine pores extending in the axial direction. Ceria and catalytic noble metal components are carried on the carrying layer to form a monolith catalyst for purifying exhaust gas. In this case, <=0.1 mol/l ceria is carried on the part in the upstream side viewed in the direction of the stream of exhaust gas in the supporting body, and 0.1 to 0.3 mol/l cerial is carried on the part in the downstream side. Furthermore, as for the catalytic noble metal components, the carrying quantity in the upstream side is regulated to 5 to 30% to the carrying quantity in the downstream side. The catalyst improves a rising property (warming up effect) at the time of low temp. exhaust. |
