An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine. The oxidation catalyst comprises: a substrate; a capture material for capturing at least one sulfur containing impurity in the exhaust gas produced by the diesel engine; wherein the capture material comprises a metal for reacting with an oxide of sulfur in the exhaust gas and particles of a refractory oxide, wherein the particles of the refractory oxide have a mean specific surface area ?50 m.sup.2/g; and a catalytic region disposed on the substrate; wherein the catalytic region comprises a catalytic material comprising a platinum group metal (PGM) selected from the group consisting of platinum (Pt), palladium (Pd) and a combination of platinum (Pt) and palladium (Pd).

A method of preparing a hydrogenation catalyst, for example, a phthalate hydrogenation catalyst, comprising contacting a silica support having a median pore size of at least about 10 nm with a silylating agent to form an at least partially coated silica support, calcining said coated silica support to form a treated silica support, and depositing a noble metal, preferably ruthenium, on the treated silica support, and optionally contacting the treated silica support with an optional chelating agent to form the hydrogenation catalyst; a hydrogenation catalyst prepared by that method; and a method of hydrogenating unsaturated hydrocarbons, such as phthalates, in which an unsaturated hydrocarbon is contacted with hydrogen gas in the presence of the hydrogenation catalyst of the invention.

A method of producing a hydrogenation catalyst, for example, a phthalate hydrogenation catalyst, comprising contacting a silica support having a medium pore size of at least about 10 nm with an acid to produce a treated silica support, and depositing a noble metal, preferably ruthenium, on the treated silica support to produce a noble metal-containing silica support, and optionally contacting the noble metal-containing silica support with a chelating agent to form the hydrogenation catalyst; a hydrogenation catalyst prepared by that method; and a method of hydrogenating unsaturated hydrocarbons, such as, phthalates, in which an unsaturated hydrocarbon is contacted with hydrogen gas in the presence of the hydrogenation catalyst of the invention.

Method of preparing a monolithic SCR catalyst with a plurality of gas flow channels comprising the steps of (a) providing a monolithic shaped substrate with a plurality of parallel gas flow channels; (b) coating the substrate with a washcoat slurry comprising titania; (c) drying and calcining the washcoat slurry; (d) impregnating the dried and calcined washcoat with an 10 aqueous impregnation solution comprising a precursor of a vanadium oxide; (e) drying the thus coated and impregnated washcoat at a drying rate of 5 mm/min or less along flow direction through the gas flow channels; and 15 (f) activating the dried, coated and impregnated washcoat by calcining.

The present invention provides a methane oxidation catalyst comprising one or more noble metals supported on zirconia, wherein the zirconia comprises tetragonal zirconia and monoclinic zirconia, and wherein the weight ratio of tetragonal zirconia to monoclinic zirconia is in the range of from 1:1 to 31:1. The invention further provides a process for preparing a methane oxidation catalyst, a methane oxidation catalyst thus prepared and a method of oxidizing methane.

Disclosed are a catalyst, its preparation and use in selective hydrogenation, which catalyst has a porous support grain on which are deposited palladium and silver, and at least one alkali and/or alkaline earth metal; the porous support contains a refractory silica, alumina and/or silica-alumina oxide, where at least 80 wt. % of the palladium is distributed in a crust at the periphery of the support, and at least 80 wt. % of the silver is distributed in a crust at the periphery of the support, the local content of palladium at each point along the diameter of the grain follows the same course as the local content of silver.

A process for removing nitrogen protoxide from gas mixtures which 5 contain it, comprising contacting with a catalyst which contains mixed oxides of copper, manganese and rare earth metals in an amount expressed as percentage by weight of CuO, MnO and rare earth metal oxide in the lowest state of valency of 20-45% CuO, 50-60% MnO, and 5-20% rare earth metal oxide.

A method of producing a hydrogenation catalyst, for example, a phthalate hydrogenation catalyst, comprising contacting a silica support having a medium pore size of at least about 10 nm with an acid to produce a treated silica support, and depositing a noble metal, preferably ruthenium, on the treated silica support to produce a noble metal-containing silica support, and optionally contacting the noble metal-containing silica support with a chelating agent to form the hydrogenation catalyst; a hydrogenation catalyst prepared by that method; and a method of hydrogenating unsaturated hydrocarbons, such as, phthalates, in which an unsaturated hydrocarbon is contacted with hydrogen gas in the presence of the hydrogenation catalyst of the invention.

A method of washcoating a porous ceramic substrate, the method comprising: (i) pre-treating the substrate to form a pre-treated substrate; (ii) contacting the pre-treated substrate with a washcoat composition, wherein the washcoat composition comprises a washcoat solvent and a refractory material (such as a high surface area refractory material), wherein step (i) comprises pre-treating the substrate so as to substantially prevent ingress of the washcoat solvent into pores of the substrate and wherein the porous ceramic substrate comprises a plurality of channels and a plurality of micro-channels.

Disclosed in certain embodiments is a catalytic material comprising: an active precious metal component comprising platinum; a sulfur-tolerant support material comprising silica on zirconia; and a substrate having the catalytic material coated thereon.