Provided are a selective reducing catalyst for diesels and a diesel exhaust gas purification apparatus in which deterioration of NO.sub.x removal performance due to phosphorus poisoning is less likely to occur.

The selective reducing catalyst for diesels is arranged in a diesel engine, adsorbs ammonia and brings the ammonia into contact with nitrogen oxides in an exhaust gas discharged from a diesel engine to perform reduction, the selective reducing catalyst comprises: a catalyst carrier; a catalyst region provided on at least the catalyst carrier; and a phosphorus trapping region provided on at least the catalyst region, wherein the catalyst region comprises one or more selected from the group consisting of a zeolite-based catalyst containing at least zeolite and a transition metal element supported on the zeolite, a W—Ce—Zr composite oxide-based catalyst, and a vanadium-based catalyst, and the phosphorus trapping region comprises at least one or more selected from the group consisting of alumina and a rare earth-based basic oxide.

The present invention relates to a catalyzed particulate filter and methods comprising the filter for treatment of an exhaust gas from a gasoline engine, the catalyzed particulate filter comprising a gasoline particulate filter (GPF); a major catalytic layer coated onto or within an inlet side, an outlet side, or both sides of the GPF surfaces, the major catalytic layer comprising a first composition, wherein the first composition comprising a first support material; and a first platinum group metal (PGM); and a minor functional material layer placed onto or within an inlet side, an outlet side, or both sides of the GPF surfaces; the minor catalytic layer comprising a second composition; wherein the major catalytic layer has a higher loading than the minor functional material layer; the minor functional material layer is placed on top of the major catalytic layer, or the major catalytic material layer is placed on top of the minor functional layer. The catalyzed particulate filter provides an improved catalytic efficiency in conjunction with an efficient filter.

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 having low NH.sub.3 formation is disclosed. The catalyst includes a carrier and a coating material. The coating material includes a precious metal active component and a catalytic material. The precious metal active component includes a first precious metal active component and a second precious metal active component. The first precious metal active component is a composition containing Ru. The second precious metal active component is a composition containing Pt, Pd and Rh. Alternatively, the second precious metal active component is a composition containing Pd and Rh.

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 and an outlet end with an axial length L; a first catalytic region comprising a first platinum group metal (PGM) component supported on a first PGM support material, wherein the first PGM component comprises rhodium (Rh) and platinum (Pt); and wherein Pt and Rh has a weight ratio of at least 1:10.

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 and an outlet end with an axial length L; a first catalytic region comprising a first platinum group metal (PGM) component, wherein the first PGM component comprises Rh and Pt; a second catalytic region comprising a second PGM component, wherein the second PGM component comprises Pd; and wherein the first PGM component has a Pt to Rh ratio of at least 1:20.

High surface area, high entropy oxides comprising multiple metal cations in a single-phase fluorite lattice material enables intrinsic catalytic activity without platinum group metals, tunable oxygen storage capacity, and thermal stability. These properties can be obtained through a facile sol-gel synthesis to provide a low-temperature route for production of phase-pure multi-cationic oxides. The resulting materials achieved significantly higher surface area and catalytic performance, taking advantage of all the properties endowed by the various cations in the composition.

An exhaust gas purification catalyst showing resistance to peeling and high purification performance is provided. The present invention is an exhaust gas purification catalyst including a base material and a catalyst layer disposed on the base material. The catalyst layer includes a catalytic metal, a first metal oxide, and a second metal oxide having a higher heat resistance than that of the first metal oxide. When Dx is an area-based average particle diameter of the first metal oxide determined from an arbitrary cross section of the catalyst layer and Dy is an area-based particle diameter of the second metal oxide 22 measured from the cross section of the catalyst layer, a ratio of the Dy to the Dx (Dy/Dx) is 5 or more, and the Dy is 7 μm or more. In the catalyst layer, pore volume of pores having pore diameters 30 nm or more measured by a nitrogen adsorption method is 0.28 cm.sup.3/g or more.

A catalytic converter system having oxygen storage materials is disclosed and methods for determining whether to reactivate oxygen storage materials and monitoring failure events of the oxygen storage materials are also disclosed.