| 摘要 |
PURPOSE:To reduce the consumption of a catalytic noble metal without deteriorating purification performance by packing plural honeycomb catalysts using the same catalytic noble metal in a catalyst container, and varying the respective temp. characteristics in the flow direction of the exhaust gas. CONSTITUTION:The catalytic converter device is obtained by packing plural or two honeycomb three-element catalysts 14 and 15 in the vertically split metallic catalyst container 11 having the inlet 11A and outlet 11B for the exhaust gas through the mats 12 and 13 made of ceramic fibers. A wash coat consisting essentially of alumina and contg. cerium, etc., is applied on the inner surface of a catalyst carrier, and catalytic noble metals such as platinum and rhodium are further deposited to form the respective three-element catalysts 14 and 15. In this case, it is required that the content of the deposited catalytic noble metal in the upstream catalyst 14 is increased in the flow direction of the exhaust gas, or the amt. of the wash coat is decreased or the cell density is lowered. |
