EXHAUST GAS CLEANING CATALYSIS LAYER, EXHAUST GAS CLEANING CATALYSIS COATED STRUCTURE, AND EXHAUST GAS CLEANING METHOD USING THEM

摘要

PROBLEM TO BE SOLVED: To provide a method for removing efficiently NO_x in dilute combusion exhaust gas. ;SOLUTION: A catalyst is provided wherein silver and further tin, silica, or titania according to a request are contained in alumina having a pore structure in which Y is 70% or over of X, and Z is 20% or under of X where for a relation of a pore radius and a pore volume, a total value of the pore volume occupied by a pore of 300 Å or under pore radius is X, a total value of the pore volume occupied by a pore of 25 Å or over to and excluding 100 Å is Y, and a total volume of the pore volume occupied by a pore of 100 Å or over up to and including 300 Å is Z. Further, for the relation between the pore radius of the catalyst and its pore volume, where a total value of the pore volume occupied by a pore of 50 Å or under pore radius is V, an exhaust gas cleaning catalysis layer wherein V is 20% or over of X is applied onto an inner surface of support substrate through-hole composed of a fire resistant material having many through-holes.;COPYRIGHT: (C)1999,JPO