Abstract: A method is provided for producing a coating layer for an exhaust gas purification catalyst device that can inhibit detachment of the coating layer when the coating layer is formed on the exhaust gas purification catalyst device. The method comprises covering a substrate with a slurry that comprises carrier particles and a dispersing medium, to form a slurry layer on the substrate, and drying and firing the slurry layer to form a coating layer, wherein the carrier particles have a median diameter (D50) of 4.00 ?m or smaller, the dispersing medium comprises water and a water-soluble alcohol, and the amount of the water-soluble alcohol in the slurry is 0.50 mass % to 12.00 mass % with respect to the slurry.

Abstract: An object of the present disclosure is to provide an exhaust gas purification catalyst demonstrating superior storage of NOx contained in exhaust gas. The exhaust gas purification catalyst of the present disclosure has a substrate, a first catalyst layer containing a catalytic metal for NOx reduction and a NOx storage material and formed on the substrate, and a second catalyst layer containing a catalytic metal for NOx oxidation and formed on the first catalyst layer. In the exhaust gas purification catalyst of the present disclosure, the value obtained by dividing the volume of all large pores having a pore volume of 1000 ?m3 or more by the total volume of all medium pores of having a pore volume of 10 ?m3 to 1000 ?m3 in the second catalyst layer is 2.44 or less.

Abstract: An object of the present disclosure is to provide an exhaust gas purification catalyst demonstrating superior storage of NOx contained in exhaust gas. The exhaust gas purification catalyst of the present disclosure has a substrate, a first catalyst layer containing a catalytic metal for NOx reduction and a NOx storage material and formed on the substrate, and a second catalyst layer containing a catalytic metal for NOx oxidation and formed on the first catalyst layer. In the exhaust gas purification catalyst of the present disclosure, the value obtained by dividing the volume of all large pores having a pore volume of 1000 ?m3 or more by the total volume of all medium pores of having a pore volume of 10 ?m3 to 1000 ?m3 in the second catalyst layer is 2.44 or less.