| 摘要 |
PURPOSE:To prevent the rising of pressure loss due to the accumulation of black soot particles by providing a surface layer smoother than a part provided with a catalyst layer to a least a part of the inlet opening end surface and end part adjacent thereto of a porous ceramic honeycomb catalyst carrier. CONSTITUTION:A glass raw material low in thermal expansion is applied to the inlet opening end surface 2 and end part 3 adjacent thereto of a porous ceramic honeycomb 1 and baked to be made smooth to make active alumina hard to be applied. Thereafter, the whole of the porous ceramic honeycomb 1 is immersed in a slip consisting of active alumina and a catalytic noble metal to be coated therewith and, after the excessive slip is removed, the coated honeycomb 1 is baked to provide a catalyst layer 4. By this constitution, the accumulation of black soot particles is not almost generated on the inlet opening end surface 2 and end part 3 adjacent thereto of the porous ceramic honeycomb 1 and, even when the black soot particles are accumulated, the accumulation amount thereof is slight as shown by an imaginary line 7 and it is prevented that the through hole passages of a honeycomb catalyst become too narrow. |
