| 摘要 |
PROBLEM TO BE SOLVED: To efficiently oxidize and remove HC and SOF in a low temperature region and at the same time to suppress sulfate production by depositing a catalytic noble metal at a specified deposition density, regarding a catalyst which is produced by forming a coating layer on a support substrate and depositing the catalytic noble metal on the coating layer. SOLUTION: This oxidation catalyst for exhaust gases is constituted of a honeycomb-like support substrate 1 and a coating layer 2 formed on the surface of the support substrate 1 and Pt 3 as a catalytic noble metal is deposited only on the coating layer 2 in an upstream part 10 installed in the upstream side of the exhaust gas flow. In this case, Pt and as such to be deposited on the coating layer 2 in the upstream part 10 is deposited at 3 g/liter of the volume of the upstream part 10 or more. Moreover, the ratio of the upstream part 10 to the whole body of the oxidation catalyst is preferably set to be 80% or less of the whole volume. Meanwhile, at least one metal selected from Pt, Pd, and Rh is deposited in the coating layer in the downstream side at 0.001-1.0g, 0.001-2.0g, and 0.001-2.0g per liter of the volume of the downstream part, respectively. |
