Abstract: The exhaust gas purification device includes: a substrate including an upstream and a downstream ends; a first catalyst layer extending across a first region and containing a first rhodium-containing catalyst and a first cerium-containing oxide, the first rhodium-containing catalyst containing a first metal oxide carrier and first rhodium particles supported on the first metal oxide carrier, a mean of a particle size distribution of the first rhodium particles being 1.5 nm to 18 nm; and a second catalyst layer extending across a second region and containing a second rhodium-containing catalyst containing a second metal oxide carrier and second rhodium particles supported on the second metal oxide carrier, a cerium content in the first catalyst layer based on a volume capacity of the substrate in the first region being higher than a cerium content in the second catalyst layer based on a volume capacity of the substrate in the second region.

Abstract: The exhaust gas purification device includes: a substrate including an upstream end through which an exhaust gas is introduced and a downstream end through which the exhaust gas is discharged; a first catalyst layer containing a rhodium-containing catalyst containing a metal oxide carrier and rhodium particles supported on the metal oxide carrier, the first catalyst layer extending across a first region; and a second catalyst layer containing palladium particles and a material having a basicity higher than a basicity of the metal oxide carrier, the second catalyst layer extending across a second region. A mean of a particle size distribution of the rhodium particles is from 1.5 nm to 18 nm.

Abstract: Provided are a method for producing an exhaust gas purification material and a method for manufacturing an exhaust gas purification device that allow efficient removal of a harmful component even after exposure to a high temperature environment. The method for producing the exhaust gas purification material includes the steps, in this order, of: (a) impregnating a metal oxide carrier with a rhodium compound solution; (b) drying the metal oxide carrier impregnated with the rhodium compound solution to obtain a rhodium-containing catalyst containing the metal oxide carrier and rhodium particles supported on the metal oxide carrier; (c) heating the rhodium-containing catalyst at a temperature within a range from 700° C. to 900° C. under an inert atmosphere; and (d) mixing the rhodium-containing catalyst with a material having a basicity higher than a basicity of the metal oxide carrier.

Abstract: An exhaust gas purification catalyst including an alkaline-earth metal carried on a porous carrier in a highly dispersed state. The catalyst layer of the exhaust gas purification catalyst has an alkaline-earth metal carrying region including a porous carrier, Pt, and a sulfuric acid salt of at least one alkaline-earth metal carried on the porous carrier, wherein a value of RAe/Pt is 0.5 or more, where RAe/Pt represents the Pearson's correlation coefficient calculated using ? and ? in each pixel obtained by, for a cross section of the region, performing the area analysis by FE-EPMA under the conditions of: pixel size 0.34 ?m×0.34 ?m; and number of measured pixels 256×256; and measuring an intensity (?: cps) of a characteristic X ray of an element (Ae) of the alkaline-earth metal and an intensity (?: cps) of a characteristic X ray of Pt for each pixel.

Abstract: Provided is an exhaust gas purification device that allows improving an exhaust gas purification performance. An exhaust gas purification device of the present disclosure includes a substrate and a catalyst layer disposed on the substrate. The catalyst layer contains a porous carrier, a catalytic metal that is supported by the porous carrier and belongs to platinum group, an alkaline earth metal supported by the porous carrier, and an alkaline earth metal not supported by the porous carrier. At least a part of the alkaline earth metal supported by the porous carrier is supported inside the porous carrier.

Abstract: The present disclosure provides an exhaust gas purification catalyst having improved durability, which comprises a substrate and a catalyst coat layer formed on the substrate, the catalyst coat layer having a two-layer structure, wherein the catalyst coat layer includes an upstream portion on an upstream side and a downstream portion on a downstream side in an exhaust gas flow direction, and a part or all of the upstream portion is formed on a part of the downstream portion, wherein the downstream portion contains Rh fine particles, and wherein the Rh fine particles have an average particle size measured by a transmission electron microscope observation of 1.0 nm or more to 2.0 nm or less, and a standard deviation ? of the particle size of 0.8 nm or less.

Abstract: A supported catalyst particles include oxide carrier particles and noble metal particles supported on the oxide carrier particles, wherein the mass of the noble metal particles is less than or equal to 5 mass % based on the mass of the oxide carrier particles, and the average particle size of the noble metal particles measured by transmission electron microscopy is 1.0-2.0 nm, with the standard deviation ? less than or equal to 0.8 nm.

Abstract: Provided is an exhaust gas purification device that allows improving an exhaust gas purification performance. An exhaust gas purification device of the present disclosure includes a substrate and a catalyst layer disposed on the substrate. The catalyst layer contains a porous carrier, a catalytic metal that is supported by the porous carrier and belongs to platinum group, an alkaline earth metal supported by the porous carrier, and an alkaline earth metal not supported by the porous carrier. At least a part of the alkaline earth metal supported by the porous carrier is supported inside the porous carrier.

Abstract: An exhaust gas purification catalyst including an alkaline-earth metal carried on a porous carrier in a highly dispersed state. The catalyst layer of the exhaust gas purification catalyst has an alkaline-earth metal carrying region including a porous carrier, Pt, and a sulfuric acid salt of at least one alkaline-earth metal carried on the porous carrier, wherein a value of RAe/Pt is 0.5 or more, where RAe/Pt represents the Pearson's correlation coefficient calculated using ? and ? in each pixel obtained by, for a cross section of the region, performing the area analysis by FE-EPMA under the conditions of: pixel size 0.34 ?m×0.34 ?m; and number of measured pixels 256×256; and measuring an intensity (?: cps) of a characteristic X ray of an element (Ae) of the alkaline-earth metal and an intensity (?: cps) of a characteristic X ray of Pt for each pixel.

Abstract: The present disclosure provides an exhaust gas purification catalyst having improved durability, which comprises a substrate and a catalyst coat layer formed on the substrate, the catalyst coat layer having a two-layer structure, wherein the catalyst coat layer includes an upstream portion on an upstream side and a downstream portion on a downstream side in an exhaust gas flow direction, and a part or all of the upstream portion is formed on a part of the downstream portion, wherein the downstream portion contains Rh fine particles, and wherein the Rh fine particles have an average particle size measured by a transmission electron microscope observation of 1.0 nm or more to 2.0 nm or less, and a standard deviation a of the particle size of 0.8 nm or less.

Abstract: An apparatus for diagnosing deterioration of an NOx storage-reduction catalyst for purifying an exhaust gas discharged from an internal engine, including an intake air amount detection unit for detecting an intake air amount to the internal combustion engine, an exhaust gas temperature detection unit for detecting the temperature of an exhaust gas passing through the NOx storage-reduction catalyst, an NOx purification rate detection unit for detecting NOx in an exhaust gas flowing into the NOx storage-reduction catalyst and in an exhaust gas flowing out of the NOx storage-reduction catalyst, thereby detecting an NOx purification rate, and a diagnostic unit for, when the temperature of the exhaust gas passing through the NOx storage-reduction catalyst increases following an increase in the intake air flow rate to the internal combustion engine and in turn, the temperature of the NOx storage-reduction catalyst greatly increases over a first predetermined threshold value, calculating a difference in the NOx puri

Abstract: An apparatus for diagnosing deterioration of an NOx storage-reduction catalyst for purifying an exhaust gas discharged from an internal engine, including an intake air amount detection unit for detecting an intake air amount to the internal combustion engine, an exhaust gas temperature detection unit for detecting the temperature of an exhaust gas passing through the NOx storage-reduction catalyst, an NOx purification rate detection unit for detecting NOx in an exhaust gas flowing into the NOx storage-reduction catalyst and in an exhaust gas flowing out of the NOx storage-reduction catalyst, thereby detecting an NOx purification rate, and a diagnostic unit for, when the temperature of the exhaust gas passing through the NOx storage-reduction catalyst increases following an increase in the intake air flow rate to the internal combustion engine and in turn, the temperature of the NOx storage-reduction catalyst greatly increases over a first predetermined threshold value, calculating a difference in the NOx puri