The present disclosure provides the exhaust gas purification catalyst with the improved purification performance under the high Ga condition and the atmosphere where the A/F is rich. The present disclosure relates to an exhaust gas purification catalyst including a catalyst coating layer on a substrate, the catalyst coating layer containing a noble metal and a metal oxide, wherein in the catalyst coating layer: an average thickness of the coating layer is in a range from 50 m to 100 m; a porosity measured by a weight-in-water method is in a range from 50% by volume to 80% by volume; and high-aspect-ratio pores having an aspect ratio of 5 or more account for 0.5% by volume to 50% by volume of a whole volume of voids, the high-aspect-ratio pore having an equivalent circle diameter in a range from 2 m to 50 m in a cross-sectional image of a catalyst coating layer cross section perpendicular to an exhaust gas flow direction of the substrate and having an average aspect ratio in a range from 10 to 50, and wherein when a surface side in contact with an exhaust gas in a thickness direction of the catalyst coating layer is defined as 0% and a side in contact with the substrate is defined as 100%, 80% by mass or more of a total amount of the noble metal is present in a range from 0% to 25% or more and 70% or less.

A catalyst article and its use in an exhaust system for internal combustion engines is disclosed. The catalyst article comprises a substrate which is a wall-flow filter, a first catalyst composition, and a second catalyst composition. The first and second catalyst compositions each independently comprise an oxygen storage component (OSC) derived from a CeZr mixed oxide sol having a D90 of less than 1.3 micron and a particulate inorganic oxide having a D90 of from 1 to 20 microns.

The present invention relates to a stoichiometric-combustion spark-ignition engine comprising a specific exhaust gas system for reducing harmful exhaust gases resulting from the combustion process. The exhaust gas system consists in the through-flow direction of a three-way catalytic converter close to the engine, an oxidation catalyst and a gasoline particulate filter.

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; and a first catalytic region on the substrate; wherein the first catalytic region comprises a first platinum group metal (PGM) component and a first inorganic oxide, wherein the first PGM component comprises PGM nanoparticles, wherein the PGM nanoparticles have no more than 100 PGM atoms, and wherein the PGM nanoparticles have a mean particle size of 1 nm to 10 nm with a standard deviation (SD) no more than 1 nm.

Disclosed are a three-way catalyst product, and the use thereof in an exhaust system for an internal combustion engine. The catalyst product for exhaust gas treatment contains a carrier comprising an inlet end and an outlet end and having an axial length L; a first catalytic region starting from the inlet end and extending by a length less than the axial length L, wherein the first catalytic region contains a first palladium component; a second catalytic region starting from the outlet end and extending by a length less than the axial length L, wherein the second catalytic region contains a second palladium component; and a third catalytic region starting from the outlet end and extending by a length less than the axial length L, wherein the third catalytic region contains a third rhodium component, and the third catalytic region is stacked on the second catalytic region.

The present invention relates to a particulate filter which comprises a wall flow filter of length L and two different catalytically active coatings Y and Z, wherein the wall flow filter comprises channels E and A that extend in parallel between a first and a second end of the wall flow filter and are separated by porous walls which form the surfaces O.sub.E and O.sub.A, respectively, and wherein the channels E are closed at the second end and the channels A are closed at the first end. The invention is characterized in that the coating Y is located in the channels E on the surfaces O.sub.E and the coating Z is located in the channels A on the surfaces O.sub.A.

The present disclosure provides the exhaust gas purification catalyst with the improved purification performance under the high Ga condition and the atmosphere where the A/F is rich. The present disclosure relates to an exhaust gas purification catalyst including a catalyst coating layer on a substrate, the catalyst coating layer containing a noble metal and a metal oxide, wherein in the catalyst coating layer: an average thickness of the coating layer is in a range from 50 m to 100 m; a porosity measured by a weight-in-water method is in a range from 50% by volume to 80% by volume; and high-aspect-ratio pores having an aspect ratio of 5 or more account for 0.5% by volume to 50% by volume of a whole volume of voids, the high-aspect-ratio pore having an equivalent circle diameter in a range from 2 m to 50 m in a cross-sectional image of a catalyst coating layer cross section perpendicular to an exhaust gas flow direction of the substrate and having an average aspect ratio in a range from 10 to 50, and wherein when a surface side in contact with an exhaust gas in a thickness direction of the catalyst coating layer is defined as 0% and a side in contact with the substrate is defined as 100%, 80% by mass or more of a total amount of the noble metal is present in a range from 0% to 25% or more and 70% or less.

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; and a first catalytic region on the substrate; wherein the first catalytic region comprises a first platinum group metal (PGM) component and a first inorganic oxide, wherein the first PGM component comprises PGM nanoparticles, wherein the PGM nanoparticles have no more than 100 PGM atoms, and wherein the PGM nanoparticles have a mean particle size of 1 nm to 10 nm with a standard deviation (SD) no more than 1 nm.

Catalyzed particulate filters comprise three-way conversion (TWC) catalytic material, which comprises rhodium as the only platinum group metal, that permeates walls of a particulate filter. Such catalyzed particulate filters may be located downstream of close-coupled three-way conversion (TWC) composites in an emission treatment system downstream of a gasoline direct injection engine for treatment of an exhaust stream comprising hydrocarbons, carbon monoxide, nitrogen oxides, and particulates.

A three-way catalyst article is provided for the treatment of exhaust gas from a positive ignition engine, the catalyst article comprising: a substrate having a first layer provided thereon, wherein a second layer is provided on the first layer, wherein the first layer comprises a first metal and a first alumina, and wherein the second layer comprises a second metal and a second alumina, wherein either (i) the first metal is Pd and the second metal is Rh; or (ii) the first metal is Rh and the second metal is Pd; and wherein at least one of the first and second aluminas comprises theta alumina.