A catalyst for purification of exhaust gas in which Pd-based nanoparticles and ceria nanoparticles represented by CeO.sub.2-x, (0≤x<0.5) are supported on a composite metal oxide support containing alumina, ceria, and zirconia, wherein a molar ratio (Ce/Pd) of Ce and Pd supported on the support is 1 to 8, a proximity α between Pd and Ce is 0.15 to 0.50, wherein the proximity α is determined, based on Pd and Ce distribution maps in an element mapping image of energy dispersive X-ray analysis, by the following formula (1)

[00001]$\begin{array}{c}\alpha =\frac{{.Math.}_{j=0}^{N-1}{.Math.}_{i=0}^{M-1}\left(\left(I\left(i,j\right)-I_{\mathrm{ave}}\right)\left(T\left(i,j\right)-T_{\mathrm{ave}}\right)\right)}{\sqrt{{.Math.}_{j=0}^{N-1}{.Math.}_{i=0}^{M-1}{\left(I\left(i,j\right)-I_{\mathrm{ave}}\right)}^2-{.Math.}_{j=0}^{N-1}{.Math.}_{i=0}^{M-1}{(T\left(i,j\right)-T_{\mathrm{ave}}}^{}}}\end{array}$

Provided is an exhaust gas purification device that allows improving an exhaust gas purification performance. An exhaust gas purification device of the present disclosure includes a substrate and a catalyst layer disposed on the substrate. The catalyst layer contains a porous carrier, a catalytic metal that is supported by the porous carrier and belongs to platinum group, an alkaline earth metal supported by the porous carrier, and an alkaline earth metal not supported by the porous carrier. At least a part of the alkaline earth metal supported by the porous carrier is supported inside the porous carrier.

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 catalyst system includes an oxygen storage and release material that has at least one compound of the structure YMO.sub.3+δ, where M is selected from Mn, Co, Cu, Ce, Ti, Ni, Zn, Fe and any combination thereof, and where δ is ≥0. The oxygen storage and release material is configured to allow absorption and release oxygen depending on the conditions of a reagent stream such that sufficient oxygen is maintained for the catalytic removal of at least one of incompletely combusted hydrocarbons, CO, and NO. The catalyst system is useful in a catalytic converter such that oxygen is supplied under rich combustion conditions in an engine upstream of the catalytic converter inlet and oxygen is adsorbed and absorbed under lean rich combustion conditions in the engine.

An exhaust gas purification catalyst (C), including a three-dimensional structure (10) and a catalyst component layer (20) supported on the three-dimensional structure (10), where the average thickness of the catalyst component layer (20) is 15 μm or more to 200 μm or less, the average particle size of the catalyst component is 2 μm or more to 10 μm or less, and the catalyst component particle size variation coefficient is 10 or more and less than 50. The particle distribution of the catalyst component can be 90% or more to 99.9% or less.

The invention relates to a particulate filter for removing particles, carbon monoxide, hydrocarbons and nitrogen oxides out of the exhaust gas of combustion engines operated with stoichiometric air/fuel mixture, comprising a wall flow filter with length L and a coating Z, wherein the wall flow filter includes channels E and A which extend in parallel between a first and a second end of the wall flow filter and are separated by porous walls, which form surfaces OE or OA, and wherein the channels E are closed at the second end and the channels A are closed at the first end, characterised in that coating Z is located in the porous walls and extends from the first end of the wall flow filter over the entire length L, and includes active aluminum oxide, two different cerium/zirconium/rare earth metal mixed oxides and at least one platinum group metal.

An oxygen storage material (OSM) that exhibits enhanced redox properties, developed mesoporosity, and a resistance to sintering. The oxygen storage material (OSM) has a high oxygen storage capacity (i.e., OSC>1.5 mmol H.sub.2/g) and enhanced reducibility (i.e., bimodal TPR-H.sub.2 profile with two T.sub.max in the temperature range from 150° C. to 550° C.). The OSM is suitable for use as a catalyst and a catalyst support. The method of making the oxygen storage material comprises the preparation of a solution containing zirconium, cerium, rare earth and transition metal salts, followed by the co-precipitation of all constituent metal hydroxides with a base.

The present invention relates to a three-way catalyst (TWC) for treatment of exhaust gases from internal combustion engines operated with a predominantly stoichiometric air/fuel ratio, so called spark ignited engines.

Subject of the invention is an exhaust gas purification system for a gasoline engine, comprising in consecutive order the following devices: ⋅ a first three-way-catalyst (TWC1), a gasoline particulate filter (GPF) and a second three-way-catalyst (TWC2), ⋅ wherein the platinum-group metal concentration (PGM) of the TWC2 is greater than the PGM of the GPF, wherein the PGM is determined in g/ft3 of the volume of the device. Also disclosed are methods in which the system is used and uses of the system.

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 palladium 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; and wherein the outlet catalyst layer overlaps with the inlet catalyst layer.