| 摘要 |
A storage catalyst 3 is constituted of a supporter substrate 30, which is formed of at least one member being selected from the group consisting of Al 2 O 3 , CeO 2 , ZrO 2 , TiO 2 and zeolite, and whose specific surface area is 30 m 2 /g or more, and a coating layer 31, which includes a supporting powder including at least one member being selected from the group consisting of Al 2 O 3 , CeO 2 , ZrO 2 , TiO 2 and zeolite, a storage material for storing NO x and SO x , the storage material being supported on the supporting powder, and a noble metal being supported on the supporting powder. Since the supporter substrate 30 has a large specific surface area, a supporting amount of the storage material for storing NO x and SO x augments remarkably. Therefore, an SO x storage amount of the storage catalyst, which is put in place on an upstream side of an NO x storage-and-reduction catalyst, augments, and thereby an NO x storage amount in low-temperature regions augments. |
