A catalytic converter with excellent OSC performance and NO.sub.x purification performance. The converter includes a substrate with a cell structure through which exhaust gas flows, and a catalyst layer formed on a cell wall surface of the substrate. The catalyst layer includes a lower catalyst layer and an upper catalyst layer, the lower catalyst layer being formed on a surface of the substrate, and the upper catalyst layer being formed on a surface of the lower catalyst layer. The upper catalyst layer includes at least a zirconia support with rhodium carried thereon, and two types of ceria-zirconia-based composite oxides with different specific surface areas, each of the ceria-zirconia-based composite oxides having no rhodium carried thereon. The lower catalyst layer includes an alumina support with platinum carried thereon, and a ceria-zirconia-based composite oxide.

The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H.sub.2S emissions. The object is solved by an exhaust gas purifying catalyst in which the top layer of a catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

The exhaust gas purification device includes a substrate, a first catalyst layer, and a second catalyst layer. The substrate includes an upstream end, a downstream end, and a porous partition wall defining a plurality of cells extending between the upstream end and the downstream end. The plurality of cells include an inlet cell opening at the upstream end and sealed at the downstream end, and an outlet cell adjacent to the inlet cell sealed at the upstream end and opening at the downstream end. The first catalyst layer is disposed on a surface of the partition wall in an upstream region. In a downstream region, the second catalyst layer is disposed inside the partition wall, and a second catalyst-containing wall including the partition wall and the second catalyst layer has a porosity of 35% or more.

An automotive exhaust system includes an exhaust pipe and a catalytic converter. The catalytic converter includes a catalyst in fluid communication with the exhaust pipe, and an electric heater between the exhaust pipe and the catalyst. The electric heater includes a cellular structure that defines a plurality of smaller and larger cells. The smaller cells occupy a contiguous half of the cellular structure.

The exhaust gas purifying catalyst presented here includes a substrate and a catalyst coat layer formed on the surface of the substrate. The catalyst coat layer is formed in a laminate structure having two layers, with a first layer being nearer to the surface of the substrate and a second layer being relatively further from this surface. The second layer includes a carrier and a noble metal supported on the carrier. The first layer is a noble metal-free layer that does not contain a noble metal but does contain an OSC material having oxygen storage capacity.

The invention relates to a method for removing oxygen from hydrocarbon-containing gas mixtures, characterized in that a hydrocarbon-containing gas mixture containing 50 vol % of one or more hydrocarbons, 2 to 10 vol % of oxygen, and possibly one or more gases from the group comprising nitrogen, noble gases, hydrogen, carbon dioxide, carbon monoxide, and water is introduced into an isothermally operated reactor, in which the oxygen contained in the hydrocarbon-containing gas mixture is at least partially converted into carbon dioxide and water in the presence of one or more catalysts, wherein the specifications in vol % relate to the total volume of the hydrocarbon-containing gas mixture introduced into the reactor and add up to 100 vol % in total.

Disclosed is an exhaust gas purification catalyst carrier which includes a phosphate salt represented by formula: MPO.sub.4 (wherein M represents Y, La, or Al) or a zirconium phosphate represented by formula ZrP.sub.2O.sub.7; an exhaust gas purification catalyst containing a noble metal at least containing Rh and supported on the carrier; and an exhaust gas purification catalyst product having a catalyst support made of a ceramic or metallic material, and a layer of the exhaust gas purification catalyst, the layer being supported on the catalyst support.

There is disclosed a highly crystalline, small crystal, ferrierite zeolite prepared from a gel containing a source of silica, alumina, alkali metal and a combination of two templating agents. The resulting material includes ferrierite crystals having a particle size of about or less than about 200 nm. The desired crystal size can be achieved by using a specific composition of the gel. The purity of the material and the crystal size was determined by using X-ray powder diffraction and scanning electron microscopy. The material has excellent surface area and micropore volume as determined by nitrogen adsorption.

An exhaust gas purification device includes a substrate including an upstream end and a downstream end and having a length Ls; a first containing Pd particles, extending between the upstream end and a first position, and being in contact with the substrate; a second containing Rh particles, extending between the downstream end and a second position, and being in contact with the substrate; and a third catalyst layer containing Rh particles, extending between the upstream end and a third position, and being in contact with at least the first catalyst layer, wherein an average of a Rh particle size distribution is from 1.0 to 2.0 nm, and a standard deviation of the Rh particle size distribution is 0.8 nm or less in each of the second catalyst layer and the third catalyst layer.

The present disclosure provides a monolith substrate used for an exhaust gas purifying catalyst that improves purification performance, a method for producing such monolith substrate, and an exhaust gas purifying catalyst comprising such monolith substrate. The present disclosure relates to a monolith substrate comprising an alumina-ceria-zirconia composite oxide and alumina, a method for producing such monolith substrate, and an exhaust gas purifying catalyst comprising such monolith substrate.