Exhaust gas catalyst

Abstract

An object of the present invention is to provide an exhaust gas catalyst that can achieve high purification performance. The exhaust gas catalyst includes: a base material () having a plurality of inner wall surfaces () formed by a plurality of through holes () penetrating therethrough from a first end surface () to a 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 (X); each of the catalyst layers () is sectioned into a first region (A) extending from the first end surface () toward the second end surface () by a predetermined distance, a second region (B) extending from the second end surface () toward the first end surface () by a predetermined distance, and a third region (C) placed between the first region (A) and the second region (B); and the catalyst layer () is formed such that a distance (h) from the central axis (X) of the through hole () to an inner surface () of the catalyst layer () in the first region (A) of the catalyst layer () is smaller than a distance (h) from the central axis (X) of the through hole () to the inner surface () of the catalyst layer () in the third region (C) of the catalyst layer (), but is larger than a distance (h) from the central axis (X) of the through hole () to the inner surface () of the catalyst layer () in the second region (B).