EXHAUST GAS PURIFYING CATALYST

摘要

The present invention proposes a new exhaust gas purifying catalyst in which gas diffusibility and miscibility in a catalyst layer are high, and thereby excellent catalyst performance can be exhibited.;There is proposed an exhaust gas purifying catalyst comprising a catalyst layer comprising two or more types of inorganic porous particles each having a different particle size, a catalytically active component, and voids, wherein;
as a first characteristic, 50% or more by number of all the voids in the catalyst layer satisfies a condition of the following (formula 1);;L/2/(πS)1/2≧2  (formula 1)wherein S represents a void cross-sectional area, and L represents a void cross-sectional circumference in the (formula 1), and;as a second characteristic, in the void cross-sectional area in the catalyst layer, the average void radius, determined assuming that the void shape is a perfect circle, is 10 μm to 20 μm.

主权项

1. An exhaust gas purifying catalyst comprising a catalyst layer comprising two or more types of inorganic porous particles each having a different particle size, a catalytically active component, and voids, wherein;
as a first characteristic, the voids satisfying a condition of the following (formula 1) occupy 50% or more by number of all the voids in the catalyst layer:
L/2/(πS)1/2≧2  (formula 1) wherein S represents a void cross-sectional area, and L represents a void cross-sectional circumference in the (formula 1), and; as a second characteristic, in the void cross-sectional area in the catalyst layer, an average void radius, determined assuming that a void shape is a perfect circle, is 10 μm to 20 μm.