A catalytic 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 and a support; a second catalytic region comprising a second PGM component on a support with low ammonia storage and a first SCR catalyst; and wherein the first catalytic region is covered by at least another catalytic region.

The present invention provides an exhaust gas purification catalyst in which platinum group metal migration from a catalyst layer to a base material during high temperature duration is suppressed. The exhaust gas purification catalyst disclosed herein includes a base material, a catalyst layer, and an intermediate layer arranged between the base material and the catalyst layer. The base material contains SiC. The catalyst layer contains a platinum group metal as a catalyst component. The intermediate layer contains substantially no platinum group metal. A product of a thickness of the intermediate layer (μm) and a specific surface area (m.sup.2/g) of the intermediate layer is 1100 or more.

The technology herein disclosed provides a wall flow type exhaust gas purifying catalyst capable of establishing the compatibility between the noxious gas purifying performance and the pressure loss suppressing performance at a high level. The exhaust gas purifying catalyst herein disclosed includes a base material 11 and a catalyst layer 20. Then, a first catalyst region 22 including the catalyst layer 20 formed therein is provided on an entry side surface 16a of a partition wall 16 of the base material 11. A second catalyst region 24 including the catalyst layer 20 formed on a wall surface 18a of a pore 18 is provided in a prescribed region from an exit side surface 16b of the partition wall toward an entry side cell 12. Further, a catalyst unformed region 30 in which a catalyst layer is substantially not formed is provided between the first catalyst region 22 and the second catalyst region 24 in the thickness direction Y of the partition wall 16. As a result of this, it is possible to prevent the deposition of PMs in the second catalyst region 24 including the catalyst layer 20 formed in the pore 18, and to establish the compatibility between the noxious gas purifying performance and the pressure loss suppressing performance at a high level.

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 oxygen storage capacity (OSC) of the GPF is greater than the OSC of the TWC2, wherein the OSC is determined in mg/l of the volume of the device. The invention also relates to methods in which the system is used and uses of the system.

An exhaust gas aftertreatment system for a diesel-engined vehicle, which system comprising a NO.sub.x Storage Catalyst (NSC) followed in a downstream direction by a Catalysed Soot Filter (CSF), wherein the CSF comprises an oxidative catalyst comprising a palladium-rich weight ratio of platinum and palladium.

A low-temperature NO.sub.x storage catalyst for automobile exhaust purification and a preparation method thereof. Loading a noble metal salt solution on molecular sieve by equal volume impregnation method, wherein the noble metal salt solution comprises palladium nitrate and platinum nitrate, and the molecular sieve comprises SSZ, SAPO and BETA, then drying at 60-120° C. for 2-6 h, roasting at 500-550° C. in air for 2-5 h, and further roasting at 750-850° C. in air for 2-5 h, and then mixing with aluminum sol, ball milling and pulping, and then coating the slurry on a carrier, wherein the loading on the coating is 100-250 g/L and the noble metal content is 10-150 g/ft.sup.3, drying at 60-120° C. for 2-6 h, then roasting at 500-550° C. in air for 2-5 h, and further continuing roasting at 750-850° C. in air for 2-5 h, to obtain the catalyst. Loading the noble metals Pt and Pd into a pore channel of a molecular sieve improves NO.sub.x storage capacity of a catalyst at low temperatures, and selecting a different type of molecular sieve as an NO.sub.x storage unit and increasing a roasting temperature of a molecular sieve material on which Pt and Pd are loaded significantly increases NO.sub.x storage capacity.

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 and a first oxygen storage capacity (OSC) material, wherein the first OSC material has a fresh specific surface area (SSA) of at least 10 m.sup.2/g; and wherein the first OSC material has an SSA difference of no more than 30 m.sup.2/g between the fresh first OSC material and the aged first OSC material.

A composite structure, exhaust aftertreatment system, and method of manufacture. The composite structure includes a body that includes an array of intersecting walls that form a plurality of channels extending in an axial direction through the body such that adjacent channels are located on opposite sides of each wall. A composite material of the body includes a first phase of a porous glass or ceramic containing material. The first phase includes an internal interconnected porosity. A second phase of an electrically conductive material is included that is a continuous, three-dimensional, interconnected, electrically conductive phase at least partially filling the internal interconnected porosity of the first phase, which creates an electrical path through at least some of the walls in a lateral direction perpendicular to the axial direction between the opposite sides of the walls.

The present disclosure is directed to a system for treating an exhaust gas stream from an engine, which includes a diesel oxidation catalyst (DOC) located downstream of the engine and adapted for oxidation of hydrocarbons and carbon monoxide, an injector adapted for the addition of a reductant to the exhaust gas stream located downstream of the DOC, a catalyzed soot filter (CSF) located downstream of the injector, and a selective catalytic reduction component adapted for the oxidation of nitrogen oxides located downstream of the CSF. The CSF is adapted for oxidizing hydrocarbons and includes a selective oxidation catalyst composition on a filter with high selectivity ratio for hydrocarbon oxidation:ammonia oxidation (e.g., at least 0.6).

Provided is, for example, an exhaust gas-purifying three-way catalyst which is suppressed in particle growth due to sintering of a catalytically active component on a carrier in exposure to a high temperature and thus is enhanced in purification performance, and a method for producing the same, as well as an integral structure type exhaust gas-purifying catalyst using the same. The exhaust gas-purifying three-way catalyst of the present invention includes a composite particle which contains a base material particle having a pore size of 100 to 650 nm as measured by a mercury intrusion method and a catalytically active particle of a platinum group element supported on the base material particle, in which a content proportion of the catalytically active particle is 0.001 to 30% by mass in total in terms of metal of the platinum group element, based on a total amount of the composite particle.