Patent ID: 11992806

Abstract:
A four-way conversion catalyst for the treatment of an exhaust gas stream of a gasoline engine, the catalyst comprising a porous wall flow filter substrate comprising an inlet end, an outlet end, a substrate axial length extending between the inlet end and the outlet end, and a plurality of passages defined by porous internal walls of the porous wall flow filter substrate, wherein the plurality of passages comprise inlet passages having an open inlet end and a closed outlet end, and outlet passages having a closed inlet end and an open outlet end; wherein in the pores of the porous internal walls and on the surface of the porous internal walls, which surface defines the interface between the porous internal walls and the passages, the catalyst comprises a three-way conversion catalytic coating comprising an oxygen storage compound and a platinum group metal supported on a refractory metal oxide; wherein in the pores of the porous internal walls, the three-way conversion catalytic coating is present as in-wall-coating and on the surface of the porous internal walls, the three-way conversion catalytic coating is present as on-wall-coating; wherein in addition to said three-way conversion catalytic coating, the catalyst comprises no further coating in the pores of the porous internal walls and no further coating on the surface of the porous internal walls.