| abstract |
There is no sudden pressure loss increase immediately after the start of PM collection, the relationship between the amount of accumulated PM and pressure loss does not have hysteresis characteristics, the pressure loss in the initial state where PM is not deposited is kept low, and the surface layer is To provide a DPF that is difficult to peel off and that can effectively use the entire amount of catalyst for the oxidation treatment of PM. SOLUTION: A honeycomb catalyst body has a catalyst supported on the surface of the internal pores of the surface layer and the surface of the surface layer, and the catalyst area ratio occupied by the catalyst in the surface layer cross section of the surface layer on the inflow side: A, the void area ratio occupied by the voids : B is 1% <A / B <90% in the central portion in the thickness direction of the surface layer, and includes the surface of the surface layer on the inflow side and the average from the surface to 1/3 depth of the surface layer thickness. The relationship between the catalyst area ratio A1 and the catalyst area ratio A2 at the center of the surface layer is A1 / A2> 1.5. [Selection] Figure 3A |