The present disclosure is directed to a low temperature carbon monoxide (LT-CO) oxidation catalyst composition for abatement of exhaust gas emissions from a lean burn engine. The LT-CO oxidation catalyst composition includes an oxygen storage component (OSC), a first platinum group metal (PGM) component, and a promoter metal, wherein the OSC is impregnated with the first PGM component and the promoter metal and the LT-CO oxidation catalyst composition is effective for oxidizing carbon monoxide (CO) and hydrocarbons (HC) under cold start conditions. Further provided are catalytic articles including the LT-CO oxidation catalyst composition, which may optionally further include a diesel oxidation catalyst (DOC) composition (giving an LT-CO/DOC article). Further provided is an exhaust gas treatment system including such catalytic articles, and methods for reducing a HC or CO level in an exhaust gas stream using such catalytic articles.

The present disclosure provides an exhaust gas purification catalyst improved in OSC performance while maintaining an exhaust gas purification performance, which comprises a substrate and at least one catalyst layer formed on the substrate, wherein an uppermost catalyst layer contains a catalyst metal, a first OSC material having a pyrochlore structure, and a second OSC material having a higher oxygen storage/release rate than the first OSC material, wherein the uppermost catalyst layer consists of an upstream catalyst layer and a downstream catalyst layer, and wherein a proportion of a mass of the second OSC material based on a total mass of the first OSC material and the second OSC material is in a specific range in each of the upstream catalyst layer and the downstream catalyst layer.

The present invention relates to a diesel oxidation catalyst comprising a carrier body having a length L extending between a first end face and a second end face, and differently composed material zones A and B arranged on the carrier body, wherein material zone A comprises platinum, palladium, rhodium or a mixture of any two or more thereof applied to a cerium-zirconium mixed oxide, and material zone B comprises platinum, palladium or platinum and palladium applied to a carrier oxide B.

The presently claimed invention provides an emission control catalyst article comprising a substrate having an inlet axial end and an outlet axial end, a bottom washcoat layer coated on the 60 to 100% length of the substrate from the inlet axial end to the outlet axial end, and a top washcoat layer coated on the 60 to 100% length of the substrate from the inlet or the outlet or both end of the substrate such that the top coat covers at least 60% of the length of the bottom washcoat layer, wherein at least part of the top washcoat layer and/or the bottom washcoat layer comprises a first portion and a second portion, wherein the first portion begins at the inlet axial end or the outlet axial end of the substrate and exhibits a platinum group metal concentration of 2 to 100 times higher than the concentration of a platinum group metal in the second portion, wherein the first portion comprises 5-50% of the substrate volume and exhibits a three-dimensional axial and/or radial zone arrangement starting from the inlet axial end of the substrate or the outlet axial end or both, wherein the platinum group metal loading in the first portion is 10 to 1000 g/ft, as determined axially from a first end of the first portion to a second end of the first portion. The platinum group metal of the first portion is deposited by spraying a platin group metal precursor solution using an apparatus comprising a spray nozzle connected to the dosing unit via a second supply tube, a control arm device connected to the spray nozzle, wherein said control arm device is adapted to allow the 3-D positioning of the nozzle relative to a substrate face and adapt the radial and/or axial deposition of the platinum group metal within the individual channels.

The exhaust gas purification device includes: a substrate including an upstream end through which an exhaust gas is introduced and a downstream end through which the exhaust gas is discharged; a first catalyst layer containing a rhodium-containing catalyst containing a metal oxide carrier and rhodium particles supported on the metal oxide carrier, the first catalyst layer extending across a first region; and a second catalyst layer containing palladium particles and a material having a basicity higher than a basicity of the metal oxide carrier, the second catalyst layer extending across a second region. A mean of a particle size distribution of the rhodium particles is from 1.5 nm to 18 nm.

Certain selective catalytic reduction (SCR) articles, systems and methods provide for high NOx conversion while at the same time low N.sub.2O formation. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles have zoned coatings containing copper-containing molecular sieves disposed thereon, where for example a concentration of catalytic copper in an upstream zone is lower than the concentration of catalytic copper in a downstream zone.

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; a first catalytic region beginning at the inlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first palladium component; a second catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the second catalytic region comprises a second palladium component; a third catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the third catalytic region comprises a third rhodium component; and wherein the third catalytic region overlies the second catalytic region.

An exhaust gas purifying catalyst (10) according to the present invention is an exhaust gas purifying catalyst including the first catalyst layer (12). The first catalyst layer (12) includes the first section (14) and the second section (15) in the exhaust gas flow direction. The first section (14) is located on the upstream side in the exhaust gas flow direction relative to the second section (15). A catalyst layer (16) contains a catalytically active component including a specific element. The concentration of the specific element in the catalyst layer (12) is higher in the first section (14) than in the second section (15), in terms of mass per unit volume. When the first section is divided in half along the thickness direction of the first catalyst layer (12), the ratio of a1 to a2, a1/a2, is 1.1 or more, where a1 represents the mass of the specific element that is present on the surface side of the catalyst layer (12) and a2 represents the mass of the specific element that is present on the other side than the surface side of the catalyst layer.

The present invention provides an exhaust gas purification catalyst including a base material 11 and a catalyst layer 20 provided on the base material 11. The catalyst layer 20 includes: a catalyst metal; and a carrying material 21 carrying the catalyst metal. The carrying material 21 includes: an OSC material 22 having an oxygen storage capacity; and a carrier 23 other than the OSC material. The OSC material 22 has a mean particle diameter Dx of 1.5 μm or more which is larger than the mean particle diameter Dy of the carrier 23 other than the OSC material 22.

A catalyst article is provided including a substrate including a plurality of passageways, and further including a first and a second oxidation region including a first and a second subset of said plurality of passageways. A first catalyst composition is coating at least a portion of each passageway of the first oxidation region and positioned as a sole PGM-containing catalyst layer, or a zoned portion thereof, or as a top PGM-containing catalyst layer, or a zoned portion thereof, in the first oxidation region. A second catalyst composition is coating at least a portion of each passageway of the second oxidation region and positioned as a sole PGM-containing catalyst layer, or a zoned portion thereof, or as a top PGM-containing catalyst layer, or a zoned portion thereof, in the second oxidation region. The Pt:Pd weight ratio is greater in the first catalyst composition than in the second catalyst composition.