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; an inlet catalyst layer beginning at the inlet end and extending for less than the axial length L, wherein the inlet catalyst layer comprises an inlet palladium component; an outlet catalyst layer beginning at the outlet end and extending for less than the axial length L, wherein the outlet catalyst layer comprises an outlet rhodium component; and wherein the outlet catalyst layer overlaps with the inlet catalyst layer.

An oxidation catalyst is described for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a substrate; a first washcoat region disposed on the substrate, wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material; a second washcoat region adjacent to the first washcoat region, wherein the second washcoat region comprises a second platinum group metal (PGM) and a second support material; a third washcoat region disposed on the substrate, wherein the third washcoat region comprises a third platinum group metal (PGM) and a third support material; and wherein either: (i) the third washcoat region is adjacent to the second washcoat region; or (ii) the second washcoat region is disposed or supported on the third washcoat region. Also described are uses and methods involving the oxidation catalyst.

Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and met-al compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter includes a combined SCR and oxidation catalyst being arranged on the dispersion side and within wall of the filter; and a palladium including catalyst arranged on the permeation side and within wall of the filter facing the permeation side.

Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and metal compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter comprises a combined SCR and oxidation catalyst arranged at least on the dispersion side and/or within wall of the filter, the combined SCR and oxidation catalyst comprises palladium, a vanadium oxide and titania.

The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of a lean burn engine. The emission treatment system includes a lean NO.sub.x trap (LNT) in fluid communication with and downstream from the lean burn engine and a low-temperature NO.sub.x adsorber (LT-NA) in fluid communication with and downstream of the LNT. Further provided is a method for abating NO.sub.x in an exhaust stream from a lean burn engine utilizing the disclosed system.

An object of the present invention is to provide an exhaust gas purification catalyst including a wall-flow substrate and a catalyst layer, and having an improved exhaust gas purification performance, and, in order to achieve such an object, the present invention provides an exhaust gas purification catalyst including: a wall-flow substrate, first catalyst layers; and second catalyst layers; wherein the first catalyst layers and the second catalyst layers satisfy the following expressions (1) to (3):

L1<L2  (1)

T1<T2  (2)

WC1>WC2  (3)

wherein L1 represents the length of the first catalyst layers, L2 represents the length of the second catalyst layers, T1 represents the thickness of the rising portions of the first catalyst layers, T2 represents the thickness of the rising portions of the second catalyst layers, WC1 represents the mass of the first catalyst layers per unit volume of the portion of the substrate provided with the first catalyst layers, and WC2 represents the mass of the second catalyst layers per unit volume of the portion of the substrate provided with the second catalyst layers.

The present disclosure generally relates to emission control catalyst articles comprising a platinum group metal (PGM) enriched zone, methods of making such emission control catalyst articles, and methods of using such emission control catalyst articles.

The present invention relates to an exhaust gas treatment system for treating exhaust gas from a lean burn combustion engine, wherein said exhaust gas comprises hydrocarbons and NOx, the exhaust gas treatment system comprising: (i) a means for injecting hydrocarbons into an exhaust gas stream; (ii) a diesel oxidation catalyst (DOC) comprising a substrate and a catalyst coating provided on the substrate, wherein the catalyst coating comprises one or more platinum group metals, wherein the one or more platinum group metals comprise platinum; (iii) a means for injecting a nitrogenous reducing agent into an exhaust gas stream; and (iv) a multifunctional catalyst (MFC) comprising an oxidation catalyst, and a selective catalytic reduction (SCR) catalyst for the selective catalytic reduction of NOx, wherein the MFC comprises a substrate and a catalyst coating provided on the substrate, wherein the catalyst coating comprises the oxidation catalyst and the SCR catalyst, wherein the oxidation catalyst comprises one or more platinum group metals, wherein the one or more platinum group metals comprise palladium and/or platinum, and wherein the SCR catalyst comprises a zeolitic material loaded with copper and/or iron; wherein the means for injecting hydrocarbons, the DOC, the means for injecting a nitrogenous reducing agent, and the MFC are located in sequential order in a conduit for exhaust gas, wherein the means for injecting hydrocarbons into an exhaust gas stream is located upstream of the DOC, wherein the DOC is located upstream of the MFC, and wherein the means for injecting a nitrogenous reducing agent into the exhaust gas stream is located between the DOC and the MFC. Furthermore, the present invention relates to a method for the treatment of exhaust gas using the exhaust gas treatment system according to the present invention, and to a method for the preparation of an exhaust gas treatment system according to the present invention.

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.

A composite, zone-coated, dual-use ammonia (AMOX) and nitric oxide oxidation catalyst (12) comprises: a substrate (5) having a total length L and a longitudinal axis and having a substrate surface extending axially between a first substrate end (I) and a second substrate end (O); two or more catalyst washcoat zones (1; 2) comprised of a first catalyst washcoat layer (9) comprising a refractory metal oxide support material and one or more platinum group metal components supported thereon and a second catalyst washcoat layer (11) different from the first catalyst washcoat layer (9) and comprising a refractory metal oxide support material and one or more platinum group metal components supported thereon, which two or more catalyst washcoat zones (1; 2) being arranged axially in series on and along the substrate surface, wherein a first catalyst washcoat zone (1) having a length L.sub.1, wherein L.sub.1<L, is defined at one end by the first substrate end (I) and at a second end (13) by a first end (15) of a second catalyst washcoat zone (2) having a length L.sub.2, wherein L.sub.2<L, wherein the first catalyst washcoat zone (1) comprises a first refractory metal oxide support material and one or more platinum group metal components supported thereon; and the second catalyst washcoat zone comprises a second refractory metal oxide support material and one or more platinum group metal components supported thereon; and a washcoat overlayer (G) extending axially from the first substrate end for up to 200% of the axial length of the underlying first catalyst washcoat layer, which washcoat overlayer comprising a particulate metal oxide loading of >48.8 g/l (>0.8 g/in.sup.3), wherein the particulate metal oxide is an aluminosilicate zeolite including at least one of copper, iron and manganese, wherein a total platinum group metal loading in the first catalyst washcoat zone (1) defined in grams of platinum group metal per litre of substrate volume (g/l) is different from the total platinum group metal loading in the second catalyst washcoat zone (2).