Abstract: An exhaust gas purification catalyst including at least two layers, a lower catalyst layer and upper catalyst layer, on a refractory three-dimensional structure, wherein the lower catalyst layer and upper catalyst layer independently include a precious metal, alumina, and cerium-zirconium composite oxide, and at least a portion of the upper catalyst layer is formed using a manufacturing method including: applying a slurry for forming the upper catalyst layer onto the lower catalyst layer, the slurry containing a pore connecting agent with a combustion decomposition temperature of 150° C. or more to 400° C. or less, a precious metal precursor, alumina, and cerium-zirconium composite oxide, the content ratio of the pore connecting agent being less than 20 mass % of the total solid content when heated to 1000° C.; and holding the workpiece in an oxygen containing gas at a temperature above ?150° C. and +50° C. or lower, relative to the combustion decomposition temperature.

Abstract: In order to provide an exhaust gas purification catalyst capable of purifying hydrocarbons, carbon monoxide, and nitrogen oxides in exhaust gas at low temperatures, the exhaust gas purification catalyst according to the present invention includes: a region (2) containing palladium and yttrium on a three-dimensional structure (1), and a first region (3) and a second region (4) provided on the region (2) in order from an inflow side of exhaust gas to an outflow side of exhaust gas. The concentration of yttrium contained in the first region (3) and/or the second region (4) is higher than the concentration of yttrium contained in the region (2).

Abstract: In order to provide an exhaust gas purification catalyst capable of purifying hydrocarbons, carbon monoxide, and nitrogen oxides in exhaust gas at low temperatures, the exhaust gas purification catalyst according to the present invention includes: a region (2) containing palladium on a three-dimensional structure (1), and a first region (3) and a second region (4) provided on the region (2) in order from an inflow side of exhaust gas to an outflow side of exhaust gas. The concentration of neodymium contained in the first region (3) is higher than the concentration of neodymium contained in the second region (4).

Abstract: In order to provide an exhaust gas purification catalyst capable of purifying hydrocarbons, carbon monoxide, and nitrogen oxides in exhaust gas at low temperatures, the exhaust gas purification catalyst according to the present invention includes: a region (2) containing palladium on a three-dimensional structure (1), and a first region (3) and a second region (4) provided on the region (2) in order from an inflow side of exhaust gas to an outflow side of exhaust gas. The concentration of rhodium contained in the first region (3) is higher than the concentration of rhodium contained in the second region (4).

Abstract: An object is to provide a means for suppressing a deterioration in catalytic performance even after being exposed to high temperature exhaust gas containing a phosphorus compound for a long period of time. An exhaust gas purifying catalyst including palladium supported on cerium-aluminum composite oxide containing cerium at from 3 to 60% by mass in terms of cerium oxide.

Abstract: A phosphorus compound-containing exhaust gas purifying catalyst includes: a refractory three-dimensional structure extending from a gas inflow side end surface to a gas outflow side end surface, the refractory three-dimensional structure having cell walls that define and form multiple gas flow paths, the gas flow paths running from the gas inflow side end surface to the gas outflow side end surface; a lower catalyst layer that contains Pd and is formed continuously from the gas inflow side end surface on the cell walls; a gas inflow side upper catalyst layer that contains Rh and is located as an uppermost layer on the cell walls; and a gas outflow side upper catalyst layer that contains Rh and is located as an uppermost layer on the cell walls.

Abstract: A catalyst for purification of exhaust gas containing a phosphorus compound includes: a lower catalyst layer containing at least one of noble metal provided on a refractory three-dimensional structure; and an upper catalyst layer at an inflow side of exhaust gas and an upper catalyst layer at an outflow side of exhaust gas provided on a surface of the lower catalyst layer. The upper catalyst layer at the inflow side and the upper catalyst layer at the outflow side have different concentrations of noble metal. The catalyst has an intermediate zone with a length of 3 to 23% of the overall length of the refractory three-dimensional structure provided between the upper catalyst layer at the inflow side and the upper catalyst layer at the outflow side. The intermediate zone starts from a position 10 to 38% from an end face of the catalyst at the inflow side of exhaust gas.

Abstract: A phosphorus compound-containing exhaust gas purifying catalyst includes: a refractory three-dimensional structure extending from a gas inflow side end surface to a gas outflow side end surface, the refractory three-dimensional structure having cell walls that define and form multiple gas flow paths, the gas flow paths running from the gas inflow side end surface to the gas outflow side end surface; a lower catalyst layer that contains Pd and is formed continuously from the gas inflow side end surface on the cell walls; a gas inflow side upper catalyst layer that contains Rh and is located as an uppermost layer on the cell walls; and a gas outflow side upper catalyst layer that contains Rh and is located as an uppermost layer on the cell walls.

Abstract: The present invention provides exhaust gas purification catalyst for an internal combustion engine, and exhaust gas purification method using the catalyst. The present invention provides the exhaust gas purification catalyst including a support, a first catalyst layer on an upstream side, a second catalyst layer on a downstream side, and a third catalyst layer. In the exhaust gas purification catalyst, the upstream portion of the third catalyst layer is present on the first catalyst layer, the downstream portion of the third catalyst layer is present on the second catalyst layer, and in the middle portion between the upstream portion and the downstream portion of the third catalyst layer is present between the first catalyst layer and the second catalyst layer.

Abstract: In order to provide an exhaust gas purification catalyst capable of purifying hydrocarbons, carbon monoxide, and nitrogen oxides in exhaust gas at low temperatures, the exhaust gas purification catalyst according to the present invention includes: a region (2) containing palladium on a three-dimensional structure (1), and a first region (3) and a second region (4) provided on the region (2) in order from an inflow side of exhaust gas to an outflow side of exhaust gas. The concentration of rhodium contained in the first region (3) is higher than the concentration of rhodium contained in the second region (4).

Abstract: In order to provide an exhaust gas purification catalyst capable of purifying hydrocarbons, carbon monoxide, and nitrogen oxides in exhaust gas at low temperatures, the exhaust gas purification catalyst according to the present invention includes: a region (2) containing palladium and yttrium on a three-dimensional structure (1), and a first region (3) and a second region (4) provided on the region (2) in order from an inflow side of exhaust gas to an outflow side of exhaust gas. The concentration of yttrium contained in the first region (3) and/or the second region (4) is higher than the concentration of yttrium contained in the region (2).

Abstract: In order to provide an exhaust gas purification catalyst capable of purifying hydrocarbons, carbon monoxide, and nitrogen oxides in exhaust gas at low temperatures, the exhaust gas purification catalyst according to the present invention includes: a region (2) containing palladium on a three-dimensional structure (1), and a first region (3) and a second region (4) provided on the region (2) in order from an inflow side of exhaust gas to an outflow side of exhaust gas. The concentration of neodymium contained in the first region (3) is higher than the concentration of neodymium contained in the second region (4).

Abstract: The present invention provides exhaust gas purification catalyst for an internal combustion engine, and exhaust gas purification method using the catalyst. The present invention provides the exhaust gas purification catalyst including a support, a first catalyst layer on an upstream side, a second catalyst layer on a downstream side, and a third catalyst layer. In the exhaust gas purification catalyst, the upstream portion of the third catalyst layer is present on the first catalyst layer, the downstream portion of the third catalyst layer is present on the second catalyst layer, and in the middle portion between the upstream portion and the downstream portion of the third catalyst layer is present between the first catalyst layer and the second catalyst layer.

Abstract: A catalyst for purification of exhaust gas containing a phosphorus compound includes: a lower catalyst layer containing at least one of noble metal provided on a refractory three-dimensional structure; and an upper catalyst layer at an inflow side of exhaust gas and an upper catalyst layer at an outflow side of exhaust gas provided on a surface of the lower catalyst layer. The upper catalyst layer at the inflow side and the upper catalyst layer at the outflow side have different concentrations of noble metal. The catalyst has an intermediate zone with a length of 3 to 23% of the overall length of the refractory three-dimensional structure provided between the upper catalyst layer at the inflow side and the upper catalyst layer at the outflow side. The intermediate zone starts from a position 10 to 38% from an end face of the catalyst at the inflow side of exhaust gas.

Abstract: An object is to provide a means for suppressing a deterioration in catalytic performance even after being exposed to high temperature exhaust gas containing a phosphorus compound for a long period of time. An exhaust gas purifying catalyst including palladium supported on cerium-aluminum composite oxide containing cerium at from 3 to 60% by mass in terms of cerium oxide.