摘要 |
An S storage catalyst 2 is equipped with a catalytic supporter, a catalytic metal being supported on this catalytic supporter and oxidizing SO2 to SO3, and an S storage material being supported on the catalytic supporter and storing S components therein. This S storage catalyst 2 has an exhaust-gas-inlet-side high-concentration portion 2A in which the S storage material is supported on the catalytic supporter in a high concentration, and an exhaust-gas-outlet-side low-concentration portion 2A in which the S storage material is supported on the catalytic supporter in a low concentration that is lower than that of the high-concentration portion. In accordance with this S storage catalyst 2, it is possible to maintain the S storing performance favorably, even in a case where exhaust-gas temperatures are low, while keeping the material cost from rising steeply. |