Abstract: The exhaust gas-purifying catalyst of the invention includes a noble metal, and crystallites that form CZ composite metal particles which serve as a carrier supporting the noble metal and contain at least zirconium (Zr) and cerium (Ce). The CZ composite oxide particles (crystallites) further contain crystal growth-suppressing fine particles which are fine metal particles comprising primarily a metallic element M that melts at 1,500° C. or above and which suppress crystal growth by the CZ composite oxide particles. The content of the metallic element M included in the CZ composite oxide particles, expressed in terms of the oxide thereof, is 0.5 mol % or less of the total oxide.

Abstract: 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?C?O3, 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.

Abstract: Provided is an exhaust catalyst that exhibits higher NOX-reducing activities at the time of engine restart while maintaining its catalytic activities during normal traveling. This invention provides an exhaust cleaning catalyst comprising a substrate and a catalyst coating layer that includes CeO2. Catalyst coating layer is constituted in its thickness direction with multiple coating layers. In a top coating layer located at the outermost surface, the CeO2 content in a top coating layer's upstream portion is less than the CeO2 content in a top coating layer's downstream portion; and the CeO2 content in the top coating layer's upstream portion is less than the CeO2 content in a lower coating layer. The CeO2 content per liter of catalyst volume in the entire coating layer is 10 g/L to 30 g/L.

Abstract: Provided is an exhaust cleaning catalyst that exhibits higher NOX-reducing activities at the time of engine restart while maintaining its catalytic activities during normal traveling. This invention provides an exhaust cleaning catalyst including a substrate and a catalyst coating layer including CeO2. Catalyst coating layer is constituted in its thickness direction with multiple coating layers. In a top coating layer located at the outermost surface, the CeO2 content in a top coating layer's upstream portion is less than the CeO2 content in a top coating layer's downstream portion. In a bottom coating layer near substrate, the CeO2 content in a bottom layer's downstream portion is less than the CeO2 content in a bottom coating layer's upstream portion.

Abstract: An exhaust gas-purifying catalyst includes a support and a catalytic metal supported thereby. The support includes a composite oxide represented by AO.xB2-?C?O3, wherein A represents at least one of an element having a valence of 1 and an element having a valence of 2, B represents an element having a valence of 3, C represents one or more elements selected from iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, x represents a numerical value of 1 to 6, and a represents a numerical value greater than 0 and less than 2. The catalytic metal includes one or more precious metals selected from rhodium, palladium, and platinum.

Abstract: An exhaust cleaning catalyst, with which precious metal sintering is inhibited and which has greater exhaust cleaning abilities, has a substrate and a catalyst coating layer provided on the substrate. The catalyst coating layer has a precious metal that serves as an oxidation and/or reduction catalyst. The precious metal has Rh-containing metal particles in which rhodium (Rh) coexists with a base metal selected among platinum group elements excluding rhodium. The Rh-containing metal particles have an average rhodium content of 0.1% to 5% by mole with the total amount of the base metal and rhodium being 100% by mole.

Abstract: An object of the present invention is to provide a catalyst for exhaust gas purification, by which exhaust gas can be efficiently purified within a wide temperature range from low to high temperatures. This object can be achieved by using a catalyst for exhaust gas purification, containing a substrate, a lower layer disposed on the substrate, and an upper layer disposed on the lower layer, wherein the lower layer contains: a lower catalytic layer that contains a first material having oxygen storage/release capacity and a first catalytic metal supported on the first material; and a non-catalytic layer that contains a second material having oxygen storage/release capacity but does not contain catalytic metal; in which the lower catalytic layer and the non-catalytic layer are laminated in any order; and an upper catalytic layer that contains a second catalytic metal.

Abstract: The exhaust gas-purifying catalyst of the invention includes a noble metal, and crystallites that form CZ composite metal particles which serve as a carrier supporting the noble metal and contain at least zirconium (Zr) and cerium (Ce). The CZ composite oxide particles (crystallites) further contain crystal growth-suppressing fine particles which are fine metal particles comprising primarily a metallic element M that melts at 1,500° C. or above and which suppress crystal growth by the CZ composite oxide particles. The content of the metallic element M included in the CZ composite oxide particles, expressed in terms of the oxide thereof, is 0.5 mol % or less of the total oxide.

Abstract: 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.

Abstract: 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 m2/g or more.

Abstract: An exhaust cleaning catalyst, with which precious metal sintering is inhibited and which has greater exhaust cleaning abilities, has a substrate and a catalyst coating layer provided on the substrate. The catalyst coating layer has a precious metal that serves as an oxidation and/or reduction catalyst. The precious metal has Rh-containing metal particles in which rhodium (Rh) coexists with a base metal selected among platinum group elements excluding rhodium. The Rh-containing metal particles have an average rhodium content of 0.1% to 5% by mole with the total amount of the base metal and rhodium being 100% by mole.

Abstract: Provided is an exhaust cleaning catalyst that exhibits higher NOX-reducing activities at the time of engine restart while maintaining its catalytic activities during normal traveling. This invention provides an exhaust cleaning catalyst including a substrate and a catalyst coating layer including CeO2. Catalyst coating layer is constituted in its thickness direction with multiple coating layers. In a top coating layer located at the outermost surface, the CeO2 content in a top coating layer's upstream portion is less than the CeO2 content in a top coating layer's downstream portion. In a bottom coating layer near substrate, the CeO2 content in a bottom layer's downstream portion is less than the CeO2 content in a bottom coating layer's upstream portion.

Abstract: Provided is an exhaust catalyst that exhibits higher NOX-reducing activities at the time of engine restart while maintaining its catalytic activities during normal traveling. This invention provides an exhaust cleaning catalyst comprising a substrate and a catalyst coating layer that includes CeO2. Catalyst coating layer is constituted in its thickness direction with multiple coating layers. In a top coating layer located at the outermost surface, the CeO2 content in a top coating layer's upstream portion is less than the CeO2 content in a top coating layer's downstream portion; and the CeO2 content in the top coating layer's upstream portion is less than the CeO2 content in a lower coating layer. The CeO2 content per liter of catalyst volume in the entire coating layer is 10 g/L to 30 g/L.

Abstract: An exhaust gas-purifying catalyst includes a substrate, and a catalytic layer facing the substrate and including a precious metal, alumina, an oxygen storage material, and a sulfate of an alkaline-earth metal having an average particle diameter falling within a range of 0.01 to 0.70 ?m, the average particle diameter being obtained by observation using a scanning electron microscope. Another exhaust gas-purifying catalyst includes a substrate, and a catalytic layer formed on the substrate using slurry containing a precious metal, alumina, an oxygen storage material, and a sulfate of an alkaline-earth metal having an average particle diameter falling within a range of 0.01 to 0.70 ?m, the average particle diameter being obtained by observation using a scanning electron microscope.

Abstract: An exhaust gas-purifying catalyst includes first particles of oxygen storage material, second particles of one or more acidic oxides interposed between the first particles, and third particles of one or more precious metal elements interposed between the first particles, wherein a spectrum of a characteristic X-ray intensity for one of constituent elements of the acidic oxide(s) other than oxygen and a spectrum of a characteristic X-ray intensity for one of the precious metal element(s) that are obtained by performing a line analysis using energy-dispersive X-ray spectrometry along a length of 500 nm have a correlation coefficient of 0.70 or more.

Abstract: An exhaust gas-purifying catalyst includes first particles of oxygen storage material, second particles of one or more rare-earth elements other than cerium and/or compounds thereof interposed between the first particles, and third particles of one or more precious metal elements interposed between the first particles, wherein a spectrum of a characteristic X-ray intensity for one of the rare-earth element(s) and a spectrum of a characteristic X-ray intensity for one of the precious metal element(s) that are obtained by performing a line analysis using energy-dispersive X-ray spectrometry along a length of 500 nm have a correlation coefficient of 0.68 or more.

Abstract: A method for producing an exhaust gas purifying catalyst including a composite oxide represented by the following general formula (3), the method including a primary baking step of baking a coprecipitate obtained from an aqueous mixed salt solution of respective elements, a citrate complex obtained from an aqueous citric acid mixed salt solution of salts of the respective elements and citric acid, or a precipitate obtained from an alkoxide mixed solution of the respective elements at 500 to 1200° C., the respective elements constituting the exhaust gas purifying catalyst represented by the following general formula (3), including A, B and Fe but excluding Pd; a step of adding an aqueous solution of Pd salt to a primary composite oxide obtained through the primary baking step to give a precursor composition; and a secondary baking step of baking the precursor composition at 800 to 1400° C., AO.x(B2-y-ZFeyPdZO3-?) (3).

Abstract: Provided is a catalyst composition capable of preventing decrease in catalytic activity due to grain growth of noble metal under high temperature or under change in oxidation reduction or further for long term use, and of achieving excellent catalytic activity over a long time. The catalyst composition containing a composite oxide represented by the following general formula (1): AO.x(B2-yCyO3-?)??(1) (wherein A represents an element selected from monovalent elements, divalent elements and lanthanides; B represents a trivalent element; and C represents a noble metal; x represents an integer of 1 to 6; y represents an atomic ratio satisfying the following relation; 0<y<2; and a represents a deficient, atomic ratio of oxygen atoms) is prepared.

Abstract: An exhaust gas-purifying catalyst whose activity is less prone to be decreased even in the case where used in a high-temperature atmosphere containing oxygen at a high concentration can be realized. The catalytic layer of the catalyst includes an oxide particle, a simple oxide of alkaline-earth element or rare-earth element, and alumina and/or aluminum hydroxide. The oxide particle contains an oxide of rare-earth element and/or zirconium, a composite oxide and a precious metal. The composite oxide contains an alkaline-earth element and at least one of the rare-earth element and zirconium. The composite oxide and a part of the precious metal form a solid solution.

Abstract: Provided is a method for purifying exhaust gas discharged from an internal combustion engine of a vehicle, using an exhaust gas purifying catalyst including a composite oxide represented by the following general formula AO.x(B2-yCyO3-?), wherein A represents an element selected from monovalent elements, divalent elements and lanthanides; B represents a trivalent element; and C represents a noble metal; x represents an integer of 1; y represents an atomic ratio satisfying the following relation: 0<y<2; and ? represents a deficient atomic ratio of oxygen atoms; and wherein the composite oxide has a spinel type crystal phase, and wherein the exhaust gas purifying catalyst removes carbon monoxide (CO) exhaust gas discharged from the internal combustion engine of the vehicle.