The invention relates to a catalyst system for reducing nitrogen oxides, which comprises a nitrogen oxide storage catalyst and an SCR catalyst, wherein the nitrogen oxide storage catalyst consists of at least two catalytically active washcoat layers on a supporting body, wherein a lower washcoat layer A contains cerium oxide, an alkaline earth compound and/or alkali compound, as well as platinum and palladium, and an upper washcoat layer B, which is arranged over the washcoat layer A, contains cerium oxide, platinum and palladium, and no alkali compound and no alkaline earth compound. The invention also relates to a method for converting NOx in exhaust gases of motor vehicles that are operated by means of engines that are operated in a lean manner.

An exhaust system for a compression ignition engine comprising an oxidation catalyst for treating carbon monoxide (CO) and hydrocarbons (HCs) in exhaust gas from the compression ignition engine, wherein the oxidation catalyst comprises: a platinum group metal (PGM) component selected from the group consisting of a platinum (Pt) component, a palladium (Pd) component and a combination thereof; an alkaline earth metal component; a support material comprising a modified alumina incorporating a heteroatom component; and a substrate, wherein the platinum group metal (PGM) component, the alkaline earth metal component and the support material are disposed on the substrate.

The present invention relates to a catalyst comprising a support body A having a length L.sub.A designed as a flow substrate, a support body B of length L.sub.B designed as a wall-flow filter, and material zones A1, A2, B1, and B2, wherein the support body A comprises material zones A1 and A2 and the support body B comprises material zones B1 and B2, wherein material zone A1 contains a cerium oxide, an alkaline earth metal compound and/or an alkali metal compound, and also platinum and/or palladium, and material zone A2 contains cerium oxide, and also platinum and/or palladium, and is free of alkali metal and alkaline earth metal compounds, material zone B1 contains palladium supported on cerium oxide, and material zone B2 contains platinum supported on a support material.

Provided is catalyst material useful for the selective catalytic reduction of NOx in lean burn exhaust gas, wherein the catalyst material is a hydrothermally stable, low SAR aluminosilicate zeolite loaded with a synergistic combination of one or more transition metals, such as copper, and one or more alkali or alkaline earth metals, such as calcium or potassium.

[Summary]

[Problem]

The problem addressed by the present invention lies in providing an exhaust gas purification filter which can efficiently treat particulate matter in exhaust gas.

[Solution]

The present invention provides an exhaust gas purification filter including a substrate comprising a plurality of porous partitions, wherein the partitions form an exhaust gas flow path, a porous catalytic layer is provided on the partitions and the catalytic layer having a thickness of 10 m or greater is provided over at least 20% of the total length of the partitions in the lengthwise direction thereof, and the catalytic layer having a thickness of 10 m or greater is not present on the partitions 15 mm from an outflow side.

A NO.sub.x trap catalyst is disclosed. The NO.sub.x trap catalyst comprises a noble metal, a NO.sub.x storage component, a support, and a first ceria-containing material. The first ceria-containing material is pre-aged prior to incorporation into the NOx trap catalyst, and may have a surface area of less than 80 m.sup.2/g. The invention also includes exhaust systems comprising the NO.sub.x trap catalyst, and a method for treating exhaust gas utilizing the NO.sub.x trap catalyst.

Composites of mixed metal oxides for an exhaust gas purifying catalyst comprise the following co-precipitated materials by weight of the composite: zirconia in an amount in the range of 55-99%; titania in an amount in the range of 1-25%; a promoter and/or a stabilizer in an amount in the range of 0-20%. These composites are effective as supports for platinum group metals (PGMs), in particular rhodium.

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.

The invention provides an automotive catalyst composite effective for abating carbon monoxide, hydrocarbons, and NOx emission in an automotive exhaust gas stream, which includes a catalytic material on a carrier, the catalytic material including a plurality of core-shell support particles comprising a core and a shell surrounding the core, the core including a plurality of particles having a primary particle size distribution d.sub.90 of up to about 5 ?m, wherein the core particles comprise particles of one or more metal oxides, the shell including nanoparticles of one or more metal oxides, wherein the nanoparticles have a primary particle size distribution d90 in the range of about 5 nm to about 1000 nm (1 ?m), and one or more platinum group metals (PGMs) on the core-shell support. The invention also provides an exhaust gas treatment system and related method of treating exhaust gas utilizing the catalyst composite.

The present invention relates to new crystalline zeolite SSZ-52x prepared using a quaternary ammonium cation templating agent, for example, having the structure: ##STR00001##
wherein X.sup. is an anion which is not detrimental to the formation of the SSZ-52x. SSZ-52x is useful as a catalyst and shows improved durability, particularly with regard to NO.sub.x conversion.