EXHAUST EMISSION CONTROL CATALYST FOR DIESEL ENGINES

摘要

Exhaust emission control catalyst for diesel engines comprises: (a) a carrier backing material; (b) on a surface of this, a metallic carrier layer supporting a catalytic metal; and (c) a 170 mu m or less thick diffusion suppressing layer on the surface of the metallic carrier layer opposite to the carrier backing material. Pref. the metallic carrier layer is porous and the diffusion suppressing layer has smaller pore size than the metallic catalytic layer; a catalytic metal with weaker oxidising strength than the above catalytic metal is supported on the diffusion suppressing layer; an SO2 trapping catalytic metal is supported on the diffusion suppressing layer; and a diffusion suppressing layer is placed between the carrier backing material and the metallic carrier layer.