The present disclosure provides the exhaust gas purification catalyst capable of efficiently converting HC in the upstream region relative to the exhaust gas flow direction in the exhaust gas purification catalyst and capable of efficiently converting NOx in the downstream region relative to the exhaust gas flow direction in the exhaust gas purification catalyst while maintaining the good warming-up performance. The present disclosure relates to an exhaust gas purification catalyst including a monolith substrate formed by a catalyst carrier and a catalyst coat layer coated on the monolith substrate, in which the monolith substrate contains Pd, the catalyst coat layer includes a downstream coat layer, the downstream coat layer contains Rh, a density of the downstream coat layer is in a specific range, the exhaust gas purification catalyst has an upstream region (upstream portion) relative to an exhaust gas flow direction and a downstream region (downstream portion) excluding the upstream region and the upstream portion has a Pd concentration higher than a Pd concentration in the downstream portion.

There is provided a structure including: a substrate including a first and a second ends, and a porous partition wall defining a first and a second cells extending between the first and the second ends; a first catalyst; and a second catalyst. In a first area, the first catalyst is disposed on a first surface of the partition wall, and the partition wall with the first catalyst disposed on the partition wall is impermeable to gas. In a second area, the first catalyst is not provided, the second catalyst is disposed in a region including at least a part inside the partition wall, the part facing the first cell, and the partition wall with the second catalyst disposed in the partition wall is permeable to gas. In a third area, any of the first catalyst or the second catalyst is not provided, and the partition wall is permeable to gas.

A catalyst article for treating a flow of a combustion exhaust gas comprises: a catalytically active substrate comprising one or more channels extending along an axial length thereof through which, in use, a combustion exhaust gas flows, the one or more channels having a first surface for contacting a flow of combustion exhaust gas; wherein the substrate is formed of an extruded vanadium-containing SCR catalyst material, wherein a first layer is provided on at least a portion of said first surface, wherein the first layer comprises an ammonia slip catalyst composition comprising one or more platinum group metals supported on titania, a silica-titania mixed oxide, a CeZr mixed oxide, or a mixture thereof, and a second layer is provided on at least a portion of the first layer and comprises an SCR catalyst composition.

An exhaust gas purification catalyst of the present invention is provided with a base 10 and a catalyst coat layer 30. The catalyst coat layer is provided with Rh and Pd as noble metal catalysts. Herein Rh is disposed in a first-stage upper layer A and a second-stage upper layer C, and Pd is disposed in the first-stage upper layer A and a first-stage lower layer B, and in a second-stage lower layer D. A mass ratio (A.sub.Pd/A.sub.Rh) of Pd to Rh, disposed in first-stage upper layer A is 0.5(A.sub.Pd/A.sub.Rh)3.

The invention relates to a three-way catalytic converter, which is suitable, in particular, for the removal of carbon monoxide, hydrocarbons and nitrogen oxides out of the exhaust gas of combustion engines operated with stoichiometric air-fuel mixture. The three-way catalytic converter is characterized in that it has a high oxygen storage capacity after aging and consists of at least two catalytically active layers.

A selective catalytic reduction system applying diesel oil as reductant for converting nitrogen oxides by means of a catalyst into diatomic nitrogen and water in a diesel engine is provided. The selective catalytic reduction system includes an oil injection system, a reactor and a number of selective catalytic reduction catalysts provided in a first section. The selective catalytic reduction system includes at least one additional section including a number of selective catalytic reduction catalysts. The at least one additional section is provided in a non-zero from the first section.

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.

A lean NO.sub.x trap catalyst and its use in an emission treatment system for internal combustion engines is disclosed. The lean NO.sub.x trap catalyst comprises a first layer for storing nitrogen oxides (NOx) under lean exhaust gas conditions and releasing and/or reducing stored NOx during rich exhaust gas conditions, and a second layer, said second layer comprising a first zone for oxidizing carbon monoxide (CO) and/or hydrocarbons (HC), and a second zone for oxidizing nitric oxide (NO), and a substrate having an inlet end and an outlet end.

The invention relates to a diesel oxidation catalyst which has a support body with a length L extending between a first end face a and a second end face b and catalytically active material zones A, B, and C arranged on the support body, whereinmaterial zone A contains palladium or platinum and palladium in a weight ratio of Pt:Pd of 1 and an alkaline earth metal and extends over 20 to 80% of the length L starting from the end face a, material zone B contains ceroxide, is free of platinum, and extends over 20 to 80% of the length L starting from the end face b, material zone C contains platinum or platinum and palladium in a weight ratio of Pt:Pd of 5, and neither material zone A nor material zone C is arranged over material zone B.

One or more embodiments relates to a method of catalytically converting a reactant gas mixture for pollution abatement of products of hydrocarbon fuel combustion. The method provides substituted mixed-metal oxides where catalytically active metals are substituted within the crystal lattice to create an active and well dispersed metal catalyst available to convert the reactant gas mixture. Embodiments may be used with gasoline and diesel fueled internal combustion engine exhaust, although specific embodiments may differ somewhat for each.