Patent ID: 7988921

Claim:
A hexagonal-cell honeycomb catalyzer for purifying an exhaust gas, the catalyzer comprising: a support that has a plurality of cells each sectioned by a wall, the support having an axial direction, each wall having a honeycomb-formed surface in section perpendicular to the axial direction, each cell being combined to each other as the support; and a purification layer that has an HC absorption layer which is formed on the honeycomb-formed surface of the wall to have a surface and which includes an HC absorbing material, the HC being included in the exhaust gas; and a three-way catalyst layer which is formed on the surface of the HC absorption layer and which includes a catalytic material, wherein, provided that the HC absorption layer has a thickness a 1 and the three-way catalyst layer has a thickness b 1 at a thin portion of the purification layer at which its thickness is minimum and the HC absorption layer has a thickness a 2 and the three-way catalyst layer has a thickness b 2 at a thick portion of the purification layer at which its thickness is maximum, a ratio of a 1 /b 1 and a ratio of a 2 /b 2 are both within a range of 1/20 to 5/1.