An exhaust gas purifying catalyst includes: a wall-flow structure substrate including an inlet cell, an outlet cell, and a porous partition; a first catalyst layer formed inside the partition such that a thickness of the first catalyst layer is between 40% and 60%, inclusive, of an overall thickness T.sub.w of the partition; and a second catalyst layer formed inside the partition such that the second catalyst layer extends across an entire region of the partition in a thickness direction thereof.

Provided is an exhaust gas purification catalyst having an improved catalyst performance while securing an OSC in an air-fuel ratio (A/F) rich atmosphere where HC poisoning is likely to occur. The present disclosure relates to an exhaust gas purification catalyst including a substrate and a catalyst coating layer coated on the substrate. The catalyst coating layer has an upstream coat layer formed from an end portion in an upstream side with respect to an exhaust gas flow direction in the exhaust gas purification catalyst and a downstream coat layer formed from an end portion in a downstream side with respect to the exhaust gas flow direction in the exhaust gas purification catalyst. The downstream coat layer includes Rh as a catalytic metal, alumina-ceria-zirconia complex oxide, and alkaline earth metal.

A system for determining isotopic composition of a gaseous sample. The system includes at least one gas chromatograph for separating the gaseous sample into gaseous components. Furthermore, the system includes a combustion furnace operatively coupled with the at least one gas chromatograph for oxidizing the gaseous components. Moreover, the system includes a water separator operatively coupled with the combustion furnace. Furthermore, the system includes an isotope-ratio mass spectrometer operatively coupled with the water separator. Moreover, the isotope-ratio mass spectrometer comprises an ion source for generating ion beams associated with each of the oxidized gaseous components and a mass analyser for receiving the generated ion beams from the ion source, wherein the mass analyser is operable to determine isotopic concentrations associated with each of the ion beams. Furthermore, the isotope-ratio mass spectrometer is operable to use the determined isotopic concentrations to determine the isotopic composition of the gaseous sample.

A system for determining isotopic composition of a gaseous sample. The system includes at least one gas chromatograph for separating the gaseous sample into gaseous components. Furthermore, the system includes a combustion furnace operatively coupled with the at least one gas chromatograph for oxidizing the gaseous components. Moreover, the system includes a water separator operatively coupled with the combustion furnace. Furthermore, the system includes an isotope-ratio mass spectrometer operatively coupled with the water separator. Moreover, the isotope-ratio mass spectrometer comprises an ion source for generating ion beams associated with each of the oxidized gaseous components and a mass analyser for receiving the generated ion beams from the ion source, wherein the mass analyser is operable to determine isotopic concentrations associated with each of the ion beams. Furthermore, the isotope-ratio mass spectrometer is operable to use the determined isotopic concentrations to determine the isotopic composition of the gaseous sample.

A nanocomposite catalyst includes a support, a multiplicity of nanoscale metal oxide clusters coupled to the support, and one or more metal atoms coupled to each of the nanoscale metal oxide clusters. Fabricating a nanocomposite catalyst includes forming nanoscale metal oxide clusters including a first metal on a support, and depositing one or more metal atoms including a second metal on the nanoscale metal oxide clusters. The nanocomposite catalyst is suitable for catalyzing reactions such as CO oxidation, water-gas-shift, reforming of CO.sub.2 and methanol, and oxidation of natural gas.

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 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.

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 disposed on at least a portion of the first surface, wherein the first layer comprises a washcoat of an ammonia slip catalyst composition comprising one or more platinum group metals supported on a particulate metal oxide support material, and wherein a layer comprising a washcoat of SCR catalyst composition is disposed on a surface in the one or more channels, wherein at least the portion of the first surface on which the first layer is disposed comprises a compound of copper, iron, cerium or zirconium or a mixture of any two or more thereof.

The invention provides a process for preparing a methane oxidation catalyst comprising a mechanochemical treatment, a methane oxidation catalyst thus prepared and a method of oxidizing methane.

The invention provides a process for preparing a methane oxidation catalyst comprising a mechanochemical treatment, a methane oxidation catalyst thus prepared and a method of oxidizing methane.