Exhaust gas purifying catalyst

An exhaust gas purifying catalyst comprising:

• a monolithic support having a plurality of cells whose sectional shape is a substantally regular N-polygon, wherein N is a natural number of more than or equal to 3;
• a hydrocarbon adsorbent layer being formed on the monolithic support and containing zeolite as a main component;
• and
• a metal-based catalyst layer being formed on the hydrocarbon adsorbent layer and containing at least one noble metal selected from the group consisting of platinum, palladium, and rhodium;
• wherein each cell sectional structure satisfies the following
• 1≦(X−Rc)/(Y−Rf)<40,
• where X is a distance from a center of gravity of the regular N-polygon to corners of the regular N-polygon, Y is a shortest distance from the center of gravity to cell sides of the regular N-polygon, Rc is a distance from a center of gravity to an inner wall surface of the hydrocarbon adsorbent layer along a line extending from the center of gravity of the regular N-polygon in the cell sectional shape to a corner of the N-polygon, and Rf is a distance from the center of gravity to the inner wall surface of the hydrocarbon adsorbent layer along a line extending from the center of gravity perpendicularly to respective sides of the regular N-polygon.