An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine comprising a catalytic region and a substrate, wherein the catalytic region comprises a catalytic material comprising: a copper (Cu) component; a platinum group metal (PGM) selected from the group consisting of (i) platinum (Pt), (ii) palladium (Pd) and (iii) platinum (Pt) and palladium (Pd); and a support material, which is a refractory oxide comprising alumina; wherein the platinum group metal (PGM) and the copper (Cu) component is each supported on the support material.

A honeycomb structure has partition walls defining a plurality of polygonal cells which become through channels for a fluid, a structure end face vertical to an axial direction has at least two cell regions possessing mutually different cell structures and surrounded by circumferential portions, and in the cell regions adjacent to each other, to first partition walls of a first cell structure of one first cell region, second partition walls of a second cell structure of the other or second cell region are tilted.

Provided are automotive catalyst composites having a catalytic material on a carrier, wherein the catalytic material comprises at least two layers. The first layer is deposited directly on the carrier and comprises a first palladium component supported on a first refractory metal oxide component, a first oxygen storage component, or a combination thereof. The second layer is deposited on top of the first layer and comprises a rhodium component supported on a second refractory metal oxide component and a second palladium component supported on a second oxygen storage component, a third refractory metal oxide component or a combination thereof. Generally these catalyst composites are used as three-way conversion (TWC) catalysts. Methods of making and using the same are also provided.

A composite oxidation catalyst for use in an exhaust system for treating an exhaust gas produced by a vehicular compression ignition internal combustion engine is disclosed. The composite oxidation catalyst comprises a honeycomb flow-through substrate monolith and two catalyst washcoat zones arranged axially in series on and along the substrate surface.

There is provided an exhaust gas purification device that shows a high HC removal performance under a condition in which a rich air-fuel mixture is introduced. The exhaust gas purification device includes a substrate, a first catalyst layer, and a second catalyst layer. The substrate includes an upstream end and a downstream end. The first catalyst layer is disposed on a surface of the partition wall in an upstream region including the upstream end of the substrate. The second catalyst layer is disposed inside the partition wall in a downstream region including the downstream end of the substrate. The first catalyst layer contains a first metal catalyst and alumina-zirconia composite oxide. The second catalyst layer contains a second metal catalyst.

The present disclosure provides Low Temperature NO.sub.x-Absorber (LT-NA) catalyst compositions, catalyst articles, and an emission treatment system for treating an exhaust gas, each including the LT-NA catalyst compositions. Further provided are methods for reducing a NO.sub.x level in an exhaust gas stream using the LT-NA catalyst articles. In particular, the LT-NA catalyst compositions include a first zeolite, a first palladium component, and a plurality of platinum nanoparticles. The LT-NA catalyst compositions exhibit enhanced regeneration efficiency with respect to NO.sub.x adsorption capacity, even after hydrothermal aging.

A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article may include: (a) a substrate having an inlet end and an outlet end defining an axial length; (b) a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve; and (c) a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve.

Methods and systems are featured for reducing harmful exhaust gas components of combustion devices such as gasoline-powered combustion engines (e.g., predominately stoichiometric running engines). The methods and systems include an underbody combination of a hydrocarbon trap (HCT), suited for cold start hydrocarbon adsorption, as well as an associated NOx trap. The system is inclusive of a control unit for extending a lean exhaust condition reaching the desorbing HCT as to avoid a deficiency in oxygen during the time period of HCT desorption. The system is also inclusive of one or more TWCs as in one associated with the underbody HCT-NOx-trap combination and/or one positioned in a close coupled position. Platinum group metals as in Pd, Rh and Pt are also featured on one, two or all three of the HCT, NOx-trap, and TWC when present.

The present invention relates to a catalyst comprising a carrier substrate of the length L extending between substrate ends a and b and two washcoat zones A and B, wherein washcoat zone A comprises a first platinum group metal and extends starting from substrate end a over a part of the length L, and washcoat zone B comprises the same components as washcoat zone A and in addition a second platinum group metal and extends from substrate end b over a part of the length L, wherein L=L.sub.A+L.sub.B, wherein L.sub.A is the length of washcoat zone A and L.sub.B is the length of substrate length B.

The present invention relates to a wall-flow filter for removing particles from the exhaust gas of combustion engines, comprising a wall-flow filter substrate of length L and coatings Z and F that differ from one another, wherein the wall-flow filter substrate has channels E and A, which extend in parallel between a first and a second end of the wall-flow filter substrate, are separated by porous walls and form surfaces O.sub.E and O.sub.A respectively, and wherein the channels E are closed at the second end and the channels A are closed at the first end, and wherein the coating Z is located in the porous walls and/or on the surfaces O.sub.A, but not on the surfaces O.sub.E, and comprises palladium and/or rhodium a cerium/zirconium mixed oxide, characterized in that the coating F is located in the porous walls and/or on the surfaces O.sub.E, but not on the surfaces O.sub.A and comprises a particulate metal compound and no noble metal.