Abstract: Disclosed is an exhaust gas purifying catalyst exhibiting excellent purification performance for a long period of time by suppressing coagulation of a noble metal. A catalyst powder comprises a noble metal and first and second compounds. In the catalyst powder, the first compound carries the noble metal and is separated from another first compound carrying a noble metal by the second compound. At least one catalyst layer comprising the catalyst powder is formed on an inner surface of a substrate. The catalyst layer has fine pores. A fine pore volume of fine pores having a fine pore diameter of greater than 0.1 ?m to less than or equal to 1 ?m is 10% to 60% of the fine pore volume of fine pores having a fine pore diameter of 0.1 ?m or less.

Abstract: An exhaust gas purifying catalyst is composed of: noble metal particles; first compounds which support the noble metal particles and suppress movement of the noble metal particles; and second compounds which encapsulate the noble metal particles and the first compounds, suppress the movement of the noble metal particles, and suppress the coagulation of the first compounds following mutual contact of the first compounds. The first compounds are a composite containing a rare earth element.

Abstract: An exhaust gas purifying catalyst includes: a catalyst particle unit having at least noble metal with a catalytic function, first oxides on which the catalyst noble metal is supported, and second oxides covering the first oxides on which the noble metal is supported. In catalyst powder formed of an aggregate of plural pieces of the catalyst particle units, at least one type of compounds selected from the group consisting of a transition element, an alkali earth metal element, an alkali metal element, and a rare earth element, which is a promoter component, are contained.

Abstract: A catalyst for purifying exhaust gas that provides a superior catalytic performance even at a high temperature by increasing the durability of the promoter. The catalyst for purifying exhaust gas includes a promoter clathrate wherein a promoter component particle is covered with a high heat-resistant oxide. A promoter active species is contained in the promoter clathrate. The catalytic active species are located adjacent to the promoter clathrates. The catalytic active species has a precious metallic particle having a catalyst activity, a metallic oxide particle for bearing the precious metallic particle and a metallic oxide placed around the metallic oxide particle and the precious metallic particle.

Abstract: A catalyst which suppresses aggregation of metal particles and which has superior heat resistance. In the catalyst, metal particles are supported by a surface of a carrier while being partially embedded therein.

Abstract: A method of producing catalyst powder of the present invention has a step of precipitating a noble metal particle (2) and a porous carrier (1) in a reversed micelle substantially simultaneously; and a step of precipitating a transition metal particle (3) in the reversed micelle. By this method, it is possible to obtain catalyst powder which restricts an aggregation of the noble metal particles even at a high temperature and is excellent in a catalytic activity.

Abstract: A high heat-resistive catalyser formed as a catalyst including a composite particle composed of a noble metal particle and a co-catalytic metal compound particle contacting, as a metal or as an oxide, with the noble metal particle, and a substrate carrying the noble metal particle and the co-catalytic metal compound particle, is produced by having a noble metal salt aqueous solution and a co-catalytic metal salt aqueous solution concurrently provided in a reverse micelle preparing reverse micellar solution containing a noble metal precursor and a co-catalytic metal precursor, and having a substrate carrying a composite particle comprising the noble metal precursor and the co-catalytic metal precursor concurrently reduced as a noble metal particle and a co-catalytic metal particle, respectively.

Abstract: In a powdery catalyst (1), a porous carrier (2) has a complex part (3) configured to hold a noble metal particle (4), the complex part being composed of a transition metal material and a constituent material of the porous carrier (2).

Abstract: A catalyst producing method comprises preparing reverse micellar solution including an aqueous solution containing at least a noble metal element as a catalytic active component, and carrying the catalytic active component by a substrate to establish them into a catalyst precursor; and spraying the emulsion solution containing the catalyst precursor in an inert gas atmosphere to obtain a dried catalyst precursor, and firing the obtained dried catalyst precursor in an air atmosphere. A catalyst is obtained by the catalyst producing method.

Abstract: A method of producing catalyst powder of the present invention has a step of precipitating any one of a noble metal particle (5) and a transition metal particle (10) in a reversed micelle (1); a step of precipitating, in the reversed micelle (1) in which any one of the noble metal particle (5) and the transition metal particle (10) is precipitated, a porous support material (7) which supports the noble metal particle (5) and the transition metal particle (10); and a step of precipitating the other of the noble metal particle (5) and the transition metal particle (10) in the reversed micelle (1) in which any one of the noble metal particle (5) and the transition metal particle (10) is precipitated. By this method, it is possible to obtain catalyst powder capable of maintaining initial purification performance thereof even if being exposed to the high temperature.

Abstract: An exhaust gas purifying catalyst of the present invention has a substrate, and a catalyst layer formed on an inner wall of the substrate and composed of at least a single layer. The catalyst layer contains a carrier supporting noble metal. Further, a maximum height of profile of a surface of a top layer in the catalyst layer is not less than 2 ?m and not more than 50 ?m, and the top layer contains the carrier supporting noble metal.

Abstract: An exhaust gas purifying catalyst for an internal combustion engine of an automotive vehicle. The exhaust gas purifying catalyst comprises a monolithic substrate. A first catalytic layer is formed on the monolithic substrate. The first catalytic layer contains at least one noble metal selected from the group consisting of rhodium, platinum and palladium, compound of at least one metal selected from the group consisting of alkali metal, alkaline earth metal and rare earth metal, and alumina. Additionally, a second catalytic layer is formed on the first catalytic layer and contains rhodium, at least one noble metal selected from the group consisting platinum and palladium, compound of at least one metal selected from the group consisting of alkali metal, alkaline earth metal and rare earth metal, and alumina. A content of the compound of the at least one metal in the second catalytic layer is larger than that in the first catalytic layer.

Abstract: A method of producing catalyst powder of the present invention has a step of precipitating a carrier in a reversed micelle, and a step of precipitating at least one of a noble metal particle and a transition metal particle in the reversed micelle in which the carrier is precipitated. By this method, it is possible to obtain catalyst powder excellent in heat resistance and high in the catalytic activity.

Abstract: A method of producing catalyst powder of the present invention has a step of precipitating a transition metal particle and a base-metal compound in a reversed micelle substantially simultaneously, and a step of precipitating a noble metal particle in the reversed micelle. By this method, it is possible to obtain catalyst powder which restricts an aggregation of noble metal particles even at the high temperature and is excellent in the catalytic activity.

Abstract: An exhaust gas purifying catalyst for an internal combustion engine of an automotive vehicle. The exhaust gas purifying catalyst comprises a monolithic substrate. A first catalytic layer is formed on the monolithic substrate. The first catalytic layer contains at least one noble metal selected from the group consisting of rhodium, platinum and palladium, compound of at least one metal selected from the group consisting of alkali metal, alkaline earth metal and rare earth metal, and alumina. Additionally, a second catalytic layer is formed on the first catalytic layer and contains rhodium, at least one noble metal selected from the group consisting platinum and palladium, compound of at least one metal selected from the group consisting of alkali metal, alkaline earth metal and rare earth metal, and alumina. A content of the compound of the at least one metal in the second catalytic layer is larger than that in the first catalytic layer.

Abstract: An exhaust gas purifying catalyst comprises a powder including a porous material having a specific surface area of 150 m2/g or more, cerium and platinum. Cerium and Platinum are loaded on the porous material. The powder has platinum dispersion of 70% or more before baking and platinum dispersion of 50% or more after baking in air at 700° C. Additionally, a reduction rate R of the platinum dispersion after the baking against the platinum dispersion before the baking is below 40%. The reduction rate R is represented by a following equation (1): R=(1?(Pt dispersion after baking)/(Pt dispersion before baking))×100??(1).

Abstract: An exhaust gas purifying catalyst comprises a catalytic ingredient including rhodium, at least one of platinum and palladium, at least one of absorption materials for absorbing NOx, a porous carrier, and a monolithic support for supporting the catalytic ingredient. The exhaust gas purifying catalyst includes a plurality of catalytic layers containing at least a part of the catalytic ingredient, and rhodium is contained at least in an outermost layer of the catalytic layers. A rhodium amount in the catalytic ingredient is 0.5 g or more for each liter of the catalyst, and a rhodium amount contained in the outermost layer accounts for 80 wt % or more of a total rhodium amount. A weight of the catalytic layer at the outermost layer is 40 wt % or below of a total weight of the catalytic layers.

Abstract: A NOx reduction catalyst for exhaust gas discharged from an automotive internal combustion engine operable in a lean region and in a range including a stoichiometric region and a rich region. The NOx reduction catalyst comprises a catalytic noble metal. Additionally, an oxygen adsorbable and releasable material is provided carrying at least a part of the catalytic noble metal. In this catalyst, the catalytic noble metal carried on the oxygen adsorbable and releasable material adsorbs SOx in the exhaust gas, in a form of at least one of sulfate and sulfite.

Abstract: An exhaust gas purifying system for an automotive internal combustion engine includes a NOx treating catalyst for reducing NOx disposed in an exhaust gas passageway of a combustion device, to reduce NOx in presence of reducing components in exhaust gas. Additionally, a hydrogen enriching device is disposed upstream of said NOx treating catalyst with respect to flow of exhaust gas from the combustion device and arranged to increase a ratio of hydrogen to total reducing components in at least one of combustion gas and exhaust gas so as to meet relations represented by following formulae (1) and (2), when reduction of NOx is carried out by the NOx treating catalyst: [H2/TR]d>[H2/TR]u  (1) [H2/TR]d≧0.

Abstract: An exhaust gas purifying system for an internal combustion engine mounted on an automotive vehicle. The exhaust gas purifying system includes an exhaust gas component concentration regulating device disposed in an exhaust gas passageway of the engine, for regulating concentrations of gas components in exhaust gas discharged from the engine such that the concentrations of carbon monoxide and hydrogen are respectively not more than 2.0% by volume and not less than 0.5% by volume and such that a volume concentration ratio of [hydrogen/carbon monoxide] is not smaller than 0.5, in rich and stoichiometric conditions of exhaust gas. Additionally, a NOx adsorbing and reducing catalyst is disposed in the exhaust gas passageway downstream of the exhaust gas component concentration regulating device, for adsorbing nitrogen oxides in a lean condition of the exhaust gas and reducing the nitrogen oxides into nitrogen in the rich and stoichiometric conditions.