Patent ID: 9694354
Date: 2017-07-04
CPC Classifications: B01D,B01J,F01N,Y02T,Y10T

Claim:
1. An exhaust gas catalyst comprising: a base material having a first end surface, a second end surface, and a plurality of inner wall surfaces formed by a plurality of through holes penetrating therethrough from the first end surface to the second end surface; and a plurality of catalyst layers formed on the plurality of inner wall surfaces, respectively, wherein: each of the through holes has a central axis; the first end surface side is an exhaust gas inflow side and the second end surface side is an exhaust gas outflow side; each catalyst layer is sectioned into a first region extending from the first end surface toward the second end surface by a predetermined distance, a second region extending from the second end surface toward the first end surface by a predetermined distance, and a third region placed between the first region and the second region; the third region of the catalyst layer is closer to the first end surface side than to the second end surface side; each catalyst layer is formed such that a distance from the central axis of the through hole to an inner surface of the catalyst layer in the first region of the catalyst layer is smaller than a distance from the central axis of the through hole to the inner surface of the catalyst layer in the third region of the catalyst layer, but larger than a distance from the central axis of the through hole to the inner surface of the catalyst layer in the second region of the catalyst layer; each catalyst layer has a uniform thickness in an entire region including the first region, the second region and the third region; in each region, each catalyst layer has a constant height; the plurality of catalyst layers is made of the same composition in a whole region including the first region, the second region, and the third region, at least one dummy layer is formed between the inner wall surface and the catalyst layer in the first region, and at least one dummy layer is formed between the inner wall surface and the catalyst layer in the second region; and the base material is a monolith honeycomb base material made of a heat-resistant ceramic.