Abstract: A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprises: a substrate; and a catalytic region on the substrate; wherein the catalytic region comprises a platinum group metal (PGM) component, an oxide, and a rare earth metal component; wherein the oxide is an inorganic oxide, an oxygen storage component (OSC) material, or a mixture thereof; wherein the rare earth metal component concentration by element on the surface of the oxide per unit specific surface area of the oxide is 1 ?mol/m2 to 20 ?mol/m2.

Abstract: A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end, an outlet end with an axial length L; an inlet catalyst layer beginning at the inlet end and extending for less than the axial length L, wherein the inlet catalyst layer comprises an inlet rhodium component and an inlet platinum component; an outlet catalyst layer beginning at the outlet end and extending for less than the axial length L, wherein the outlet catalyst layer comprises an outlet rhodium component.

Abstract: A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprises: a substrate; and a catalytic region on the substrate; wherein the catalytic region comprises a platinum group metal (PGM) component, an oxide, and a rare earth metal component; wherein the oxide is an inorganic oxide, an oxygen storage component (OSC) material, or a mixture thereof; wherein the rare earth metal component concentration by element on the surface of the oxide per unit specific surface area of the oxide is 1 ?mol/m2 to 20 ?mol/m2.

Abstract: An exhaust gas catalyst where the catalyst efficiency is improved by enhancing diffusion of the exhaust gas in a catalyst layer. An exhaust gas catalyst comprises at least a carrier and a plurality of layers formed on the carrier. At least one of the layers has pores therein, and at least one other layer has pores therein and contains, as catalyst components, a noble metal, alumina and a complex oxide mainly containing ceria, zirconia and one or more rare earth elements other than cerium.

Abstract: An exhaust gas catalyst where the catalyst efficiency is improved by enhancing diffusion of the exhaust gas in a catalyst layer. An exhaust gas catalyst comprises at least a carrier and a plurality of layers formed on the carrier. At least one of the layers has pores therein, and at least one other layer has pores therein and contains, as catalyst components, a noble metal, alumina and a complex oxide mainly containing ceria, zirconia and one or more rare earth elements other than cerium.

Abstract: Exhaust gas clean-up catalysts that contain one or two or more noble metals chosen from the group platinum (Pt), rhodium (Rh), ruthenium (Ru), Iridium (Ir), osmium (Os) and other noble metals, and at least one of tungsten (W) metal or tungsten oxide and, optionally, at least one of niobium (Nb) metal, niobium oxide, molybdenum (Mo) metal, or molybdenum oxide, and which can also contain the metal oxide(s) ceria and/or zirconia if necessary, are especially useful for cleaning up hydrocarbons in exhaust gases.

Abstract: Exhaust gas clean-up catalysts that contain one or two or more noble metals chosen from the group platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), Iridium (), osmium (Os) and other noble metals and one, two or more metal oxides chosen from the group tungsten (W), niobium b) and molybdenum (Mo) oxides, and which can also contain the metal oxide(s) ceria and/or zirconia if necessary, are especially useful for cleaning up hydrocarbons in exhaust gases.

Abstract: A layout structure of catalytic converters, used for an engine transversely arranged in an engine room formed in a front portion of a vehicle, includes a front catalytic converter connected to an exhaust manifold arranged in a forward direction of the vehicle with respect to the engine, and a rear catalytic converter connected to an exhaust manifold arranged in a backward direction of said vehicle, wherein the rear catalytic converter is arranged to be offset from a central position of the engine arranged along a widthwise direction of the vehicle by a predetermined distance. With this structure, the rear catalytic converter can be cooled in the same manner as the front catalytic converter. In addition, the rear catalytic converter is formed into a cylindrical member having an elliptic/oval cross-sectional shape with a major axis coinciding with a longitudinal direction of the vehicle, thus increasing the area of a heat-dissipating surface of the rear catalytic converter.

Abstract: An exhaust system for an engine having two groups of cylinders includes a small capacity catalytic converter disposed in an exhaust manifold for one group of cylinders and a larger capacity catalytic converter disposed in an exhaust manifold for another group of cylinders. The exhaust system also includes a primary catalytic converter, having a capacity larger than both the small and larger catalytic converters, disposed in an exhaust pipe commonly connected to the exhaust manifolds.