In an aspect of the present disclosure, a catalyst includes an oxide containing 5 or more types of rare earth elements and 1 or more types of platinum group elements. The catalyst has a configuration entropy of a cation site determined based on (i) the number of types of the rare earth elements and the platinum group element that can be arranged in the cation site in a crystalline structure of the oxide, and (ii) each proportion of the rare earth elements and the platinum group element of more than 1.7R, where R is a gas constant.

An object of the present invention is to provide a powder of a CeO.sub.2—ZrO.sub.2-based complex oxide which enables to achieve an improvement in the purification performance at a low to middle temperature of an exhaust gas purification catalyst, and, in order to achieve the above-mentioned object, the present invention provides a powder of a CeO.sub.2—ZrO.sub.2-based complex oxide, wherein a pore volume with from-10-to-100-nm diameters after a heat treatment performed at 1,000° C. for 3 hours in an air atmosphere, is 0.35 mL/g or more, and wherein an amount of carbon dioxide desorbed after the heat treatment, as measured by a temperature programmed desorption method, is 80 μmol/g or more.

The present disclosure provides an exhaust gas purification material and an exhaust gas purification device that can efficiently remove harmful components even after being exposed to high temperature. Such exhaust gas purification material comprises metal oxide particles and noble metal particles supported on the metal oxide particles. The noble metal particles have a particle size distribution with a mean of 1.5 nm and 18 nm and a standard deviation of less than 1.6 nm.

The exhaust gas-purifying catalyst of the invention contains oxide particles having interdispersed therein A crystallites that are loaded with a noble metal and B crystallites that are not loaded with a noble metal. The A crystallites loaded with a noble metal are composed of an oxide containing at least one of zirconium (Zr) and cerium (Ce). The B crystallites not loaded with a noble metal are composed of a cerium (Ce)-containing oxide which has a higher Ce content (mol %) than the oxide making up the A crystallites. The oxide particles have a specific surface area after 5 hours of heat treatment at 1,150° C. in open air of 30 m.sup.2/g or more.

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.

A lean gasoline exhaust treatment catalyst article is provided, the article comprising a catalytic material applied on a substrate, wherein the catalytic material comprises a first composition and a second composition, wherein the first and second compositions are present in a layered or zoned configuration, the first composition comprising palladium impregnated onto a porous refractory metal oxide material and rhodium impregnated onto a porous refractory metal oxide material; and the second composition comprising platinum impregnated onto a porous refractory metal oxide material. Methods of making and using such catalyst articles and the associated compositions and systems employing such catalyst articles are also described.

When sizes of particles supporting a catalyst metal remain relatively large but sizes of particles not supporting a catalyst metal are minimized among metal oxide particles included in a catalyst coating layer, it is possible to decrease a thickness of the catalyst coating layer while maintaining durability and improve gas diffusibility of the coating layer. Therefore, a thickness of the catalyst coating is decreased without decreasing durability and a catalyst can exhibit high exhaust gas purification performance even under high load conditions.

Composites of mixed metal oxides for an exhaust gas purifying catalyst comprise the following co-precipitated materials by weight of the composite: zirconia in an amount in the range of 55-99%; titania in an amount in the range of 1-25%; a promoter and/or a stabilizer in an amount in the range of 0-20%. These composites are effective as supports for platinum group metals (PGMs), in particular rhodium.

The present invention discloses a preparation method of a catalyst with white carbon black modified by Zr—Nd—O and use thereof, and belongs to the field of catalyst technologies. In the present invention, an organic solvent evaporation induced self-assembly method is used to load Zr—Nd—O onto white carbon black to obtain a mesoporous Zr—Nd—O/white carbon black catalyst. The mesoporous Zr—Nd—O/white carbon black catalyst in the present invention has high catalytic activity, contains uniformly distributed mesopores with a relatively large average aperture, and has a simple preparation process, etc.

The present disclosure provides an exhaust gas purification material and an exhaust gas purification device that can efficiently remove harmful components even after being exposed to high temperature. Such exhaust gas purification material comprises metal oxide particles and noble metal particles supported on the metal oxide particles. The noble metal particles have a particle size distribution with a mean of 1.5 nm and 18 nm and a standard deviation of less than 1.6 nm.