This invention provides a multinary solid solution fine particle represented by Pd.sub.xRu.sub.yM.sub.z (M is at least one member selected from the group consisting of Rh, Pt, Cu, Ag, Au and Ir. x+y+z=1, x+y=0.01 to 0.99, z=0.99 to 0.01, x:y=0.1:0.9 to 0.9:0.1), a method for producing the same, and a supported catalyst.

An exhaust gas purification device includes: a substrate of wall-flow structure having an inlet cell, an outlet cell and a porous partition wall; an upstream catalyst layer provided inside the partition wall and disposed in an upstream portion, including an exhaust gas inflow end section, of the substrate; and a downstream catalyst layer provided inside the partition wall and disposed in a downstream portion, including an exhaust gas outflow end section, of the substrate. The downstream catalyst layer contains a carrier, and Rh supported on the carrier. The upstream catalyst layer contains a carrier, and Pd and/or Pt supported on the carrier.

A CON zeolite satisfying the following (1) to (2): (1) The framework is CON as per the code specified by the International Zeolite Association (IZA); and (2) It contains silicon and aluminum, and the molar ratio of aluminum to silicon is 0.04 or more.

A method for treating a crude natural gas feed stream comprising methane and having a first carbon dioxide concentration, said method comprising the steps of: subjecting the crude natural gas feed stream to a separation process to provide: a purified natural gas stream having a second carbon dioxide content which is lower than the first carbon dioxide concentration in said crude natural gas stream; and, a carbon dioxide stream comprising carbon dioxide as the major component and methane; recovering the purified natural gas steam; optionally mixing the carbon dioxide stream with make-up methane and/or make-up air; passing the carbon dioxide stream and optional make-up methane or air through a heat exchanger to raise the temperature of the stream to the desired inlet temperature T.sub.1 of an oxidation reactor; optionally mixing the carbon dioxide stream with make-up methane and/or make-up air; passing the heated stream from step (d) and any optional make-up methane and/or air to the oxidation reactor containing an oxidation catalyst, where the methane is oxidised; removing a gas stream including the products of the oxidation reaction from the reactor, said gas stream being at an outlet temperature T.sub.2 which is higher than the inlet temperature T.sub.1; passing the gas stream removed in step (g) through the heat exchanger against the carbon dioxide stream from step (a) to allow the heat to be recovered from the gas stream removed in step (g) and utilised to heat the carbon dioxide stream in step (d); and measuring the outlet temperature T.sub.2 and controlling the inlet temperature T.sub.1 by adjusting the amount of make-up methane and/or air added in step (c) and/or step (e).

A passive NO.sub.x adsorber is disclosed. The passive NO.sub.x adsorber is effective to adsorb NO.sub.x at or below a low temperature and release the adsorbed NO.sub.x at temperatures above the low temperature. The passive NO.sub.x adsorber comprises a noble metal and a molecular sieve having an LTL Framework Type. The invention also includes an exhaust system comprising the passive NO.sub.x adsorber, and a method for treating exhaust gas from an internal combustion engine utilizing the passive NO.sub.x adsorber.

Synergized platinum group metals (SPGM) with ultra-low PGM loadings employed as close-coupled (CC) three-way catalysts (TWC) systems with varied material compositions and configurations are disclosed. SPGM CC catalysts in which ZPGM compositions of binary or ternary spinel structures supported onto support oxides are coupled with commercialized PGM UF catalysts and tested under Federal Test Procedure FTP-75 within TGDI and PI engines. The performance of the TWC systems including SPGM CC (with ultra-low PGM loadings) catalyst and commercialized PGM UF catalyst is compared to the performance of commercialized PGM CC and PGM UF catalysts. The disclosed TWC systems indicate that SPGM CC TWC catalytic performance is comparable or even exceeds high PGM-based conventional TWC catalysts, with reduced tailpipe emissions.

This invention provides a multinary solid solution fine particle represented by Pd.sub.xRu.sub.yM.sub.z (M is at least one member selected from the group consisting of Rh, Pt, Cu, Ag, Au and Ir. x+y+z=1, x+y=0.01 to 0.99, z=0.99 to 0.01, x:y=0.1:0.9 to 0.9:0.1), a method for producing the same, and a supported catalyst.

The present invention relates to a methane combustion catalyst including platinum and iridium supported on a tin oxide carrier for combusting methane in a combustion exhaust gas containing sulfur oxide. In this methane combustion catalyst, in line analysis by electron probe microanalysis performed on an arbitrary cross-section thereof from a deepest catalyst portion toward a catalyst surface, a first region where all of platinum, iridium and tin are detected and a second region where tin is essentially detected but platinum is not detected are both observable. In a specific form, the catalyst includes a base catalyst layer where platinum and iridium are supported on a tin oxide carrier, and an overcoat layer including tin oxide formed on the base catalyst layer. The methane combustion catalyst of the present invention is excellent in initial activity, and is improved in durability.

A zeolite catalyst capable of maintaining a high conversion of raw materials over a long period of time, and a method of producing a lower olefin stably over a long period of time using the zeolite catalyst is to be provided. A CON zeolite catalyst containing aluminum (Al) as a constituent element, wherein the CON zeolite catalyst has a ratio ((A.sub.2/A.sub.1)100 (%)) of an integrated intensity area (A.sub.2) of signal intensity in a range from 57.5 ppm to 70 ppm to an integrated intensity area (A.sub.1) of signal intensity in a range from 45 ppm to 70 ppm is not less than 49.0% when analyzed by .sup.27Al-MAS-NMR is prepared, and a lower olefin is produced by a MTO process using the zeolite catalyst.

The present invention relates to a catalyst comprising a macroporous noble metal-containing zeolite material and a porous SiO.sub.2-containing binder, wherein the catalyst has a proportion of micropores of more than 70%, based on the total pore volume of the catalyst. The invention is additionally directed to a process for preparing the catalyst and to the use of the catalyst as an oxidation catalyst.