Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the lower layer of the 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.

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S 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.

Abstract: There is provided a catalytic converter that offers high exhaust gas cleaning performance by effectively utilizing a whole catalyst that constitutes the catalytic converter. In a catalytic converter (10), catalytic layers (2A, 2B) made of a noble metal catalyst are formed on cell wall surfaces of a substrate (1) having a cell structure, and the catalytic layers (2A, 2B) extend in a longitudinal direction of the substrate (1) along which gas flows. The substrate (1) has a central region (1A) having a relatively high cell density and a peripheral region (1B) having a relatively low cell density. The length of each of the catalytic layers (2B) in the longitudinal direction in the peripheral region (1B) is longer than the length of each of the catalytic layers (2A) in the longitudinal direction in the central region (1A).

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the lower layer of the 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.

Abstract: Provided is a catalytic converter capable of obtaining superior NOx purification performance while reducing the amount of a noble metal catalyst. A catalytic converter 10 includes: a substrate 1 having a cell structure in which exhaust gas flows; and catalyst layers 3 that are formed on cell wall surfaces 2 of the substrate 1. The catalyst layers 3 include a first catalyst layer 4 disposed on an upstream side of the substrate 1 in an exhaust gas flow direction and a second catalyst layer 5 disposed on a downstream side of the substrate in the exhaust gas flow direction. The first catalyst layer 4 is formed of a support and rhodium which is a noble metal catalyst supported on the support. The second catalyst layer 5 is formed of a support and palladium or platinum which is a noble metal catalyst supported on the support.

Abstract: A catalytic converter includes a substrate (1) and a catalyst layer (3). The catalyst layer includes a bottom catalyst layer (4), a first top catalyst layer (6) and a second top catalyst layer (7). The second top catalyst layer is provided on a downstream side relative to the first top catalyst layer. The first top catalyst layer is made of a ceria-free zirconia composite oxide support and rhodium. The second top catalyst layer is made of a ceria-containing zirconia composite oxide support and rhodium. The first top catalyst layer has a length that is X % of the entire length of the substrate. The second top catalyst layer has a length that is 100?X % of the entire length of the substrate. A ratio of a density of rhodium in the first top catalyst layer to a density of rhodium in the second top catalyst layer is at least 1 and at most 3.

Abstract: An objective of the present invention is to provide a method for producing a catalyst for exhaust gas removal having excellent heat tolerance and purification performance within a wide range of atmospheres and a catalyst obtained by the production method. The present invention relates to a method for supporting catalyst metal particles, comprising: (a) adding an iridium precursor and a palladium precursor to a solvent containing at least one member selected from the group consisting of polyvinylpyrrolidone, N-methylpyrrolidone, N-vinyl-2-pyrrolidone, and ethylene glycol; (b) adding a reducing agent to the obtained catalyst metal colloid; (c) obtaining a concentrated solution containing catalyst metal particles by subjecting the obtained solution to heat reflux; and (d) supporting the catalyst metal particles on a carrier, wherein the iridium content of the catalyst metal particles accounts for 3% to 10% by mass of the total mass of iridium and palladium.

Abstract: The exhaust gas cleaning catalyst according is provided with a substrate and a catalyst coat layer formed on a surface of the substrate. The catalyst coat layer is formed as a laminate structure having an upper layer and a lower layer. The upper layer is a Pd-free layer that does not contain Pd, and the lower layer is a Pd-containing layer. In addition, when a region of the lower layer that corresponds to 20% of the length of the exhaust gas cleaning catalyst from the exhaust gas inlet side end towards the exhaust gas outlet side of the exhaust gas cleaning catalyst is divided into four equal regions to be each 5% of the length, the relationship A>B>C is satisfied, where A, B, and C represents the Pd content in the first, second, and third region respectively.

Abstract: A catalytic converter with excellent OSC performance and Nox purification performance. The catalytic converter includes a substrate with a cell structure and a catalyst layer formed on a cell wall surface of the substrate. The catalyst layer has a catalyst layer arranged on the upstream side and a catalyst layer arranged on the downstream side in an exhaust gas flow direction on the substrate. The catalyst layer on the upstream side includes a support containing an Al2O3—CeO2—ZrO2 ternary composite oxide (ACZ material) and an Al2O3—ZrO2 binary composite oxide (AZ material), and at least Rh that is a noble metal catalyst carried on the support, and the catalyst layer on the downstream side includes a support and Pd or Pt that is a noble metal catalyst carried on the support. In the support in the catalyst layer on the upstream side, the mass proportion of ACZ material/(ACZ material+AZ material) is in the range of 0.33 to 0.

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S 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.

Abstract: A catalytic converter with excellent OSC performance and Nox purification performance. The catalytic converter includes a substrate with a cell structure and a catalyst layer formed on a cell wall surface of the substrate. The catalyst layer has a catalyst layer arranged on the upstream side and a catalyst layer arranged on the downstream side in an exhaust gas flow direction on the substrate. The catalyst layer on the upstream side includes a support containing an Al2O3—CeO2—ZrO2 ternary composite oxide (ACZ material) and an Al2O3—ZrO2 binary composite oxide (AZ material), and at least Rh that is a noble metal catalyst carried on the support, and the catalyst layer on the downstream side includes a support and Pd or Pt that is a noble metal catalyst carried on the support. In the support in the catalyst layer on the upstream side, the mass proportion of ACZ material/(ACZ material+AZ material) is in the range of 0.33 to 0.

Abstract: A catalyst converter includes: a substrate (1) having a cell structure formed of a center area (1A) having the highest cell density, a peripheral area (1C) having the lowest cell density, and an intermediate area (1B) having the cell density between that of the center area and that of the peripheral area; a first catalyst layer formed in the center area (1A); a second catalyst layer formed in the intermediate area (1B); and a third catalyst layer formed in the peripheral area (1C). A length in a longitudinal direction of the second catalyst layer is longer than that of the first catalyst layer. A length in the longitudinal direction of the third catalyst layer is longer than that of the second catalyst layer. A ratio of the length in the longitudinal direction of the first catalyst layer to the length of the substrate is 65% or more.

Abstract: Provide is a catalytic converter including a substrate which includes regions having different cell densities, in which exhaust gas purification performance is superior in all the regions of the substrate. A catalytic converter 10 includes catalyst layers in which a noble metal catalyst is supported on a support in surfaces of cell walls 2 of a substrate 1 having a cell structure in a longitudinal direction of the substrate 1 in which gas flows, in which the substrate 1 has a first region 1A having a relatively high cell density and a second region 1B having a relatively low cell density, and a ratio of a thickness of a catalyst layer 3A in the second region 1B to a thickness of a catalyst layer 3 in the first region 1A is in a range of more than 0.95 times and 1.2 times or less.

Abstract: Provided is a catalytic converter in which the entire catalyst constituting the catalytic converter can be efficiently utilized to purify exhaust gas, and the emission of hydrogen sulfide can be suppressed. A catalytic converter 10 includes catalyst layers 2A, 2B formed of a noble metal catalyst that are formed on cell wall surfaces of a substrate 1 having a cell structure in a longitudinal direction of the substrate 1 in which gas flows, in which the substrate 1 has a center region 1A having a relatively high cell density and a peripheral region 1B having a relatively low cell density, and lengths of the catalyst layers 2A, 2B of the center region 1A and the peripheral region 1B in the longitudinal direction are the same as each other, or the length of the catalyst layer 2B in the longitudinal direction is shorter than that of the catalyst layer 2A.

Abstract: An object of the present invention is to provide an exhaust gas catalyst that can achieve high purification performance.

Abstract: A catalyst converter includes: a substrate (1) having a cell structure formed of a center area (1A) having the highest cell density, a peripheral area (1C) having the lowest cell density, and an intermediate area (1B) having the cell density between that of the center area and that of the peripheral area; a first catalyst layer formed in the center area (1A); a second catalyst layer formed in the intermediate area (1B); and a third catalyst layer formed in the peripheral area (1C). A length in a longitudinal direction of the second catalyst layer is longer than that of the first catalyst layer. A length in the longitudinal direction of the third catalyst layer is longer than that of the second catalyst layer. A ratio of the length in the longitudinal direction of the first catalyst layer to the length of the substrate is 65% or more.

Abstract: A catalytic converter (10) includes a base material and a catalyst layer (3). The catalyst layer has a lower catalyst layer (4) and an upper catalyst layer (5). The upper catalyst layer is constituted by a first upper catalyst layer (6) and a second upper catalyst layer (7). The first upper catalyst layer is formed of a first carrier, which is formed of a ceria-containing oxide, and rhodium supported on the first carrier. The second upper catalyst layer is formed of a second carrier and rhodium supported on the second carrier. The second carrier does not contain ceria and is formed of one oxide selected from among zirconia and alumina. A length of the first upper catalyst layer is X % (30 to 70%) of an overall length of the base material. A length of the second upper catalyst layer is 100?X % of the overall length of the base material.

Abstract: A catalytic converter capable of uniformizing an exhaust gas flow velocity to realize uniform temperature distribution and improved purification performance, and a method for designing the catalytic converter. A catalytic converter includes a catalyst base composed of an inner base material part having inner cell holes and an outer base material part having outer cell holes, and an exhaust pipe composed of an upstream-side pipe, a catalyst housing pipe and a downstream-side pipe. In the catalytic converter, a flow path cross-sectional area of the upstream-side pipe defined as S1, a cross-sectional area of the inner base material part defined as S2, a cross-sectional area of the catalyst base defined as S3, a hydraulic diameter of the inner cell holes defined as d1 and a hydraulic diameter of the outer cell holes defined as d2, satisfy the relationship, S1?S2?S3(?0.2242 (d12/d22)2+0.1141 (d12/d22)+0.617).

Abstract: Provided is an exhaust gas control catalyst in which a catalyst layer containing at least one of Pd and Pt is formed on a substrate (1), the exhaust gas control catalyst including a first OSC material having a pyrochlore structure and an OSC material whose oxygen storage rate is faster than that of the first OSC material having a pyrochlore structure in a catalyst layer front stage (21) which is in a range from an exhaust gas upstream end of the catalyst layer to a length position which is 50% or lower of a total length of the catalyst layer.

Abstract: An exhaust gas purification catalyst is provided with a substrate and a catalyst coating layer formed on the surface of the substrate. The catalyst coating layer is formed into a layered structure having upper and lower layers, with a lower layer being closer to the surface of the substrate and an upper layer being relatively farther therefrom. The catalyst coating layer is provided with Rh and Pd as precious metal catalysts and is provided with an OSC material having an oxygen storage capacity as a support. The Rh is disposed in the upper layer of the catalyst coating layer, and the Pd is disposed in both the upper layer and the lower layer of the catalyst coating layer. At least a portion of the Pd in the upper layer and in the lower layer is supported on the OSC material. The mass ratio of the Pd disposed in the upper layer to the Pd disposed in the lower layer is not more than 0.4.