Exhaust gas purifying catalyst and method for producing the same

Abstract

The invention provies an exhaust gas purifying catalyst with an excellent effect of suppressing deterioration due to aggregation of a noble metal catalyst during endurance at high temperature, and a production method therefor. The method for producing the exhaust gas purifying catalyst that has a porous carrier and a noble metal catalyst supported thereon includes: preparing the porous carrier that contains alumina-ceria-zirconia composite oxide particles and has physical property values, after subjected to baking at 900DEG C. for 5 hours, of a pore diameter of the particles in the range of 2to 20 nm, a specific surface area of the particles in the range of 75 to 115 m2 / g, a crystallite size of a ceria-zirconia composite oxide contained in the particles in the range of 4 to 6 nm, and a bulk density of the particles in the range of 0.5 to 0.9 cm3 / g, and bringing a noble metal chemical solution having an aggregate of platinum or the like with a grain size adjusted to less than or equalto 1 nm with the use of a platinum nitric acid solution or the like, into contact with the porous carrier, so that the noble metal catalyst is supported on the porous carrier.

Description

technical field [0001] The present invention relates to an exhaust gas purification catalyst and a manufacturing method thereof. Background technique [0002] In various industries, various efforts to reduce the environmental impact load are being carried out around the world. Among them, in the automobile industry, not to mention gasoline engine vehicles with excellent fuel consumption performance, so-called hybrid vehicles and electric vehicles, etc. The popularity of environmentally friendly vehicles and the development of further performance enhancements are also growing. In addition to the development of such eco-cars, research on exhaust gas purification catalysts that purify exhaust gas exhausted from engines is also being actively conducted. [0003] The exhaust purification catalyst includes an oxidation catalyst or a three-way catalyst, NO x occlusion reduction catalysts, etc., among the exhaust gas purification catalysts, platinum (Pt) or palladium (Pd), rhodium...

AI Technical Summary

Problems solved by technology

[0012] However, regarding the effect of suppressing deterioration due to sintering of the noble metal catalyst, more specifically, regarding the effect of suppressing deterioration due to aggregation of the noble metal catalyst in high-temperature endurance, it is considered that there is room for improvement.

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