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.

The present invention relates to a catalyst comprising two layers on an inert catalyst carrier, a layer A containing at least palladium as a platinum group metal, in addition to a cerium/zirconium/lanthanum/yttrium mixed oxide, and a layer B, which is applied to layer A, containing at least rhodium as the platinum group metal, in addition to a cerium/zirconium/lanthanum/yttrium mixed oxide.

A exhaust gas purification apparatus is provided with: a substrate having a wall-flow structure and including entry-side cells, exit-side cells, and a porous partition; a first catalyst region formed in small diameter pores having relatively small pore diameters among internal pores in the partition; and a second catalyst region formed in large diameter pores having relatively large pore diameters among the internal pores in the partition. The first catalyst region contains a support and any one or two species of precious metal selected from Pt, Pd, and Rh loaded on the support, while the second catalyst region contains a support and any one or two species of precious metal selected from Pt, Pd, and Rh loaded on the support and other than at least the precious metal present in the first catalyst region.

Described are catalytic articles comprising a substrate having a washcoat on the substrate, the washcoat containing a catalytic component having a first average (D50) particle size and a functional binder component having a second average (D50) particle size in the range of about 10 nm to about 1000 nm, wherein the ratio of the first average (D50) particle size to the second average (D50) particle size is greater than about 10:1. The catalytic articles are useful in methods and systems to purify exhaust gas streams from an engine.

A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Jr and Pt.

An object of the present invention is to provide an exhaust gas purification catalyst having improved exhaust gas purifying performance (in particular, improved NOx purifying performance) at low to medium temperature, and, in order to achieve the object, the present invention provides an exhaust gas purification catalyst (10A) including: a substrate (20); and a catalyst layer (30 or 40) formed on the substrate (20), wherein the catalyst layer (30 or 40) contains rhodium element, phosphorus element and a rare earth element other than cerium element, wherein a ratio of a mass of the phosphorus element contained in the catalyst layer (30 or 40) to the mass of the rhodium element contained in the catalyst layer (30 or 40) is from 1 to 10, and wherein a ratio of a mass of the rare earth element other than cerium element in terms of an oxide thereof contained in the catalyst layer (30 or 40) to the mass of the rhodium element contained in the catalyst layer (30 or 40) is from 1 to 5.

An object of the present invention is to increase the reduction performance of nitrogen oxides compared to existing three-way catalysts; simultaneously inhibit the emission of ammonia and nitrous oxide; simplify a process by means of a method of further doping an iridium-ruthenium catalyst into a commercial three-way catalyst; and expand the scope of application. The present invention provides a catalyst for simultaneously inhibiting the emission of ammonia and nitrous oxide by doping an iridium-ruthenium catalyst component into a three-way catalyst (TWC), a diesel oxidation catalyst, or a lean NOx trap supported on a honeycomb support.

A method of manufacturing a catalyst article, the method comprising: providing a complex of a humic acid or derivative thereof, and a PGM; providing a support material; applying the complex to the support material to form a loaded support material; disposing the loaded support material on a substrate; and heating the loaded support material to form nanoparticles of the PGM on the support material.

An object of the present invention is to provide an exhaust gas purification catalyst including a wall-flow substrate and a catalyst layer, and having an improved exhaust gas purification performance, and, in order to achieve such an object, the present invention provides an exhaust gas purification catalyst including: a wall-flow substrate, first catalyst layers; and second catalyst layers; wherein the first catalyst layers and the second catalyst layers satisfy the following expressions (1) to (3):

L1<L2  (1)

T1<T2  (2)

WC1>WC2  (3)

wherein L1 represents the length of the first catalyst layers, L2 represents the length of the second catalyst layers, T1 represents the thickness of the rising portions of the first catalyst layers, T2 represents the thickness of the rising portions of the second catalyst layers, WC1 represents the mass of the first catalyst layers per unit volume of the portion of the substrate provided with the first catalyst layers, and WC2 represents the mass of the second catalyst layers per unit volume of the portion of the substrate provided with the second catalyst layers.

An oxygen storage material including a ceria-zirconia based composite oxide containing a composite oxide of ceria and zirconia, wherein the ceria-zirconia based composite oxide comprises at least one rare-earth element selected from the group consisting of lanthanum, yttrium, and neodymium, and an amount of the rare-earth element(s) contained in total is 1 to 10% by atom in terms of element relative to a total amount of cerium and zirconium in the ceria-zirconia based composite oxide, 60 to 85% by atom of the entire amount of the rare-earth element(s) is contained in a near-surface upper-layer region extending from a surface of each primary particle of the ceria-zirconia based composite oxide to a depth of 50 nm in the primary particle, and 15 to 40% by atom of the entire amount of the rare-earth element(s) is contained in a near-surface lower-layer region extending from a depth of 50 nm to a depth of 100 nm in the primary particle, a content ratio of cerium and zirconium in the ceria-zirconia based composite oxide is in a range of 40:60 to 60:40 in terms of an atomic ratio ([Ce]:[Zr]), and the ceria-zirconia based composite oxide has an intensity ratio {I(14/29) value} between a diffraction line at 2θ=14.5° and a diffraction line at 2θ=29° which satisfies the following condition:
I(14/29) value≥0.032,
where the intensity ratio {I(14/29) value} is determined from an X-ray diffraction pattern using CuKα obtained by an X-ray diffraction measurement conducted after heating in air under a temperature condition of 1100° C. for 5 hours.