Abstract: An exhaust gas purification catalyst device including a substrate and an SCR catalyst layer on the substrate, the substrate containing catalyst precious metal particles directly supported on the substrate, the catalyst precious metal particles containing Pt, and the catalyst precious metal particles having an average particle diameter of 30 to 120 nm inclusive.

Abstract: An exhaust gas purification catalyst device having a substrate and one or more catalytic noble metals supported on the substrate. The substrate has a plurality of cells partitioned by a porous wall 1 and includes ceria-zirconia compound oxide particles. A specific noble metal that is one of the one or more catalytic noble metals satisfies both the following requirements (1) and (2): (1) the noble metal 50% support depth for the specific noble metal is 30% or less of the distance from the surface of the porous wall 1 to the center of the interior of the porous wall 1, and (2) the noble metal 90% support depth for the specific noble metal is 35% or more of the distance from the surface of the porous wall 1 to the center of the interior of the porous wall 1.

Abstract: An exhaust gas purification catalytic device includes: a substrate; at least one type of noble-metal catalyst that is supported on the substrate; and a coating layer on the surface of the substrate. The substrate includes a plurality of cells which are demarcated by porous walls. The substrate and the coating layer each include ceria-zirconia composite oxide particles.

Abstract: An exhaust-gas purification apparatus includes: a honeycomb base material including a plurality of exhaust-gas flow paths partitioned by a porous wall; and one or more catalyst noble metals carried by the honeycomb base material. The catalyst noble metals are selected from the group consisting of platinum, palladium, and rhodium. The honeycomb base material has a noble metal concentrated surface section in which a 50%-by-mass noble metal carry depth for a specific noble metal that is one type among one or two catalyst noble metals is less than 50% of the distance from the surface to the center of the inside of the porous wall. The 50%-by-mass noble metal carry depth is the depth at which, when the amount of the specific noble metal carried between the surface and the center of the inside of porous wall is used as a reference, 50% by mass of specific noble metal is carried.

Abstract: The exemplary embodiments relate to an exhaust gas purification catalyst that is excellent in terms of HC purification capacity and warm-up performance.

Abstract: The exemplary embodiments relate to an exhaust gas purification catalyst that is excellent in terms of HC purification capacity and warm-up performance.