The present disclosure provides a technology of reducing migration of a noble metal catalyst in high temperature environments and reducing degradation of temperature characteristics. The production method disclosed herein includes: preparing an SiC base material 10 which has partitions 16 partitioning multiple cells and contains SiC; and forming a Pd catalyst layer 20 containing at least Pd particles 22 on surfaces of the partitions 16 of the SiC base material 10. In the production method disclosed herein, in the forming of the catalyst layer, the Pd catalyst layer 20 is formed by causing the Pd particles 22 to be carried directly on an Si member containing Si or SiC (for example, the partitions 16 of the SiC base material 10). Contacting between the Si member (SiC base material 10) and the Pd particles 22 in advance reduces migration and aggregation of the Pd particles 22 in high temperature environment and reduces degradation of temperature characteristics.

An exhaust gas-purifying catalyst includes a support and a catalytic metal as one or more precious metals supported by the support. The support includes a composite oxide having a composition represented by a general formula AB.sub.C.sub.O.sub.3, wherein A represents one or more elements selected from the group consisting of lanthanum, neodymium, and yttrium, B represents iron or a combination of iron and aluminum, C represents one or more elements selected from the group consisting of iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, and each represents a numerical value within a range of more than 0 and less than 1, and and satisfy relational formulae of > and +1.

An exhaust gas-purifying catalyst includes a support and a catalytic metal as one or more precious metals supported by the support. The support includes a composite oxide having a composition represented by a general formula AB.sub.C.sub.O.sub.3, wherein A represents one or more elements selected from the group consisting of lanthanum, neodymium, and yttrium, B represents iron or a combination of iron and aluminum, C represents one or more elements selected from the group consisting of iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, and each represents a numerical value within a range of more than 0 and less than 1, and and satisfy relational formulae of > and +1.

Provided are a catalyst for internal combustion engine exhaust gas purification, including a first catalyst component region (a) having a catalyst component layer containing Rh at a concentration of 0.1 to 3.0 g/L at a length of 3 to 30 mm on an upstream side, a second catalyst component region (b) having a catalyst component layer containing Pd at a concentration of 1.0 to 20.0 g/L at a length of 10 to 100 mm on a downstream side, and a third catalyst region (c) mainly containing rhodium at a concentration of 0.05 to 1.0 g/L and an oxygen storage material at a concentration of 30 to 150 g/L at a length of 25 to 150 mm, if necessary, on a monolithic support along a flow of the exhaust gas as a noble metal catalyst active component, and a system for purifying internal combustion engine exhaust gas using the catalyst. These suppress formation and discharge of N.sub.2O at the time of purification of exhaust gas, and make purification of NOx and HC possible with a small amount of a noble metal from the time of cold starting.

The object of the present invention is to provide an exhaust gas purifying catalyst, exhibits excellent performance for methane purification. The object can be solved by the exhaust gas purifying catalyst comprising a substrate and a catalyst layer provided on the substrate, in which the catalyst layer comprises at least one member selected from the group consisting of vanadium, niobium and tantalum; and platinum, and/or palladium.

An exhaust system for treating an exhaust gas produced by a lean burn engine comprising: (i) a NO.sub.x absorber catalyst comprising a molecular sieve catalyst disposed on a substrate, wherein the molecular sieve catalyst comprises a noble metal and a molecular sieve, wherein the molecular sieve contains the noble metal; (ii) means for introducing hydrocarbons into the exhaust gas; and (iii) a lean NO.sub.x trap; wherein the NO.sub.x absorber catalyst is upstream of both the means for introducing hydrocarbons into the exhaust gas and the lean NO.sub.x trap.

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.

A catalyst subassembly for a device for purifying exhaust gases from an internal combustion engine, in particular a diesel engine, includes an SCRF catalyst and an SCR catalyst upstream of the SCRF catalyst. The two catalysts are arranged in a common catalyst housing. The catalyst housing, the SCRF catalyst and the SCR catalyst can be selected from a modular system for different variants of the internal combustion engine.

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.

A tool for a catalyst coating apparatus to a honeycomb substrate of an exhaust gas-purifying catalyst is inserted into an outer cylinder having an axial length longer than an axial length of the honeycomb substrate supported by the outer cylinder in a state where an axial direction of the honeycomb substrate is arranged in a vertical direction. The tool comprises a cylindrical partition member having flexibility. An outer peripheral surface of the partition member faces an inner peripheral surface of an outer cylinder extension portion of the outer cylinder protruding upward with respect to an upper end surface of the honeycomb substrate. When the catalyst slurry is supplied to the upper end surface of the honeycomb substrate and an inside of an inner peripheral surface of the partition member, a lower end of the partition member is disposed in a vicinity of an upper end surface of the honeycomb substrate.