A Ce—Zr composite oxide contains cerium and zirconium, wherein an uneven distribution ratio of cerium atoms is 1.80 or less. A method for producing a Ce—Zr composite oxide includes an acid treatment step of bringing at least one selected from the group consisting of sulfuric acid, nitric acid, and hydrochloric acid, in an amount of 4 to 28 parts by mass with respect to 100 parts by mass of the raw material composite oxide, into contact with the surface of a raw material composite oxide containing cerium and zirconium, and a calcination step of calcining the treated composite oxide obtained in the acid treatment step at 400 to 1200° C. for 5 to 300 minutes.

An oxidation catalyst for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a first washcoat region comprising platinum (Pt), manganese (Mn) and a first support material; a second washcoat region comprising a platinum group metal (PGM) and a second support material; and a substrate having an inlet end and an outlet end; wherein the second washcoat region is arranged to contact the exhaust gas at the outlet end of the substrate and after contact of the exhaust gas with the first washcoat region.

The present invention disclosed an improved process for the preparation of bimetallic core-shell nanoparticles by using facile aqueous phase synthesis strategy and their application in catalysis such as selective hydrogenation of alkynes into alkenes or alkanes and CO hydrogenation to hydrocarbons.

The present invention provides a catalytic article comprising a) a first layer comprising a nickel component and a copper component supported on a ceria component, wherein the amount of the nickel component is 0.1 to 30 wt. %, calculated as nickel oxide, based on the total weight of the first layer, and wherein the amount of the copper component is 0.01 to 5.0 wt. % calculated as copper oxide, based on the total weight of the first layer; b) a second layer comprising a platinum group metal component supported on at least one of an oxygen storage component, an alumina component and a zirconia component, wherein the platinum group metal component comprises platinum, rhodium, palladium, or any combination thereof, and wherein the amount of the platinum group metal component is 0.01 to 5.0 wt. % based on the total weight of the second layer; and c) a substrate, wherein the first layer and the second layer are separated by a barrier layer or a gap.

An object of the present invention is to provide an exhaust gas purification catalyst which can exhibit sufficient purification performance even under a high Ga condition. The present invention relates to an exhaust gas purification catalyst comprising a substrate and a catalyst coating layer formed on the substrate, wherein the catalyst coating layer comprises catalyst particles, the catalyst coating layer having an upstream region extending by 40 to 60% of the entire length of the substrate from an upstream end of the catalyst in the direction of an exhaust gas flow and a downstream region corresponding to the remainder portion of the catalyst coating layer, the composition of the catalyst particle of the upstream region being different from that of the downstream region. The downstream region in the direction of an exhaust gas flow has a structure where a void is included in a large number, and furthermore high-aspect-ratio pores having an aspect ratio of 5 or more account for a certain percentage or more of the whole volume of voids. Thus, the exhaust gas purification catalyst exhibits enhanced purification performance.

An oxidation catalyst for treating an exhaust gas from a diesel engine comprises: a first washcoat region for oxidising carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material, and wherein the first washcoat region does not comprise manganese or an oxide thereof; a second washcoat region for oxidising nitric oxide (NO), wherein the second washcoat region comprises platinum (Pt), manganese (Mn) and a second support material comprising a refractory metal oxide, which is silica-alumina or alumina doped with silica in a total amount of 0.5 to 45% by weight of the alumina, wherein the platinum (Pt) is disposed or supported on the second support material and the manganese (Mn) is disposed or supported on the second support material; and a substrate having an inlet end and an outlet end, and wherein the first washcoat region is a first washcoat layer and the second washcoat region is a second washcoat layer, and the second washcoat layer is disposed on the first washcoat layer; and wherein when the oxidation catalyst comprises a hydrocarbon adsorbent, which is a zeolite, then the first washcoat region further comprises the hydrocarbon adsorbent.

A cold start catalyst is disclosed. The cold start catalyst is effective to adsorb NO.sub.x and hydrocarbons (HC) at or below a low temperature and to covert and release the adsorbed NO.sub.x and HC at temperatures above the low temperature. The cold start catalyst comprises a molecular sieve catalyst and a supported platinum group metal catalyst. The molecular sieve catalyst consists essentially of a noble metal and a molecular sieve. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst, and a method for treating exhaust gas from an internal combustion engine utilizing the cold start catalyst.

The present invention pertains to a catalyst for use in the selective catalytic reduction (SCR) of nitrogen oxides comprising a monolithic substrate and a coating A, which comprises an oxidic metal carrier comprising an oxide of titanium and a catalytic metal oxide which comprises an oxide of vanadium wherein the mass ratio vanadium/titanium is 0.07 to 0.26.

A compression ignition internal combustion engine (30) for a heavy-duty diesel vehicle comprising an exhaust system (32) comprising a composite oxidation catalyst (12, 42) and a soot filter substrate (44, 50) disposed downstream from the composite oxidation catalyst comprising: a substrate (5), preferably a honeycomb flow-through substrate monolith, 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 catalyst washcoat zones (1, 2) arranged axially in series on and along the substrate surface, wherein a first catalyst washcoat zone (1) having a length L.sub.1 and comprising a first catalyst washcoat layer (9), wherein L.sub.1<L, is defined at one end by the first substrate end (I) and at a second end by a first end (15) of a second catalyst washcoat zone (2) having a length L.sub.2 and comprising a second catalyst washcoat layer (11), wherein L.sub.2<L, wherein the second catalyst washcoat zone (2) is defined at a second end thereof by the second substrate end (O), and wherein the first substrate end (I) of the composite oxidation catalyst (12, 42) is oriented to an upstream side and wherein the first catalyst washcoat zone (1) comprises a first refractory metal oxide support material and two or more platinum group metal components supported thereon comprising both platinum and palladium at a weight ratio of platinum to palladium of <1; and the second catalyst washcoat zone (2) 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 (I) comprising a particulate metal oxide having a loading of >48.8 g/l (>0.8 g/in.sup.3), 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 greater than a total platinum group metal loading in the second catalyst washcoat zone (2) and wherein the first catalyst washcoat zone (1) comprises one or more first alkaline earth metal components, preferably barium, supported on the first refractory metal oxide support material.

An oxidation catalyst for treating an exhaust gas from a compression ignition engine, which oxidation catalyst comprises: a substrate; a first washcoat region comprising palladium (Pd) and a first support material comprising cerium oxide; and a second washcoat region comprising platinum (Pt) and a second support material.