CATALYST FOR CLEANING EXHAUST GAS

摘要

PROBLEM TO BE SOLVED: To propose a new catalyst for cleaning exhaust gas that gives high gas diffusion and mixing in a catalyst bed and thus achieves excellent catalyst performance.SOLUTION: A catalyst for cleaning exhaust gas has a catalyst bed including two or more kinds of inorganic porous particles of a different size, a catalytic active component, and voids. A first characteristic of the catalyst is that 50% or more of the number of the all voids in the catalyst bed satisfy the condition of the following expression 1. A second characteristic of the catalyst is that an average void radius is 10 μm-20 μm assuming the void has complete roundness in a cross-sectional area of the void in the catalyst bed. L/2/(&pgr;S)≥2 (expression 1) (S: cross-sectional area of the void, L: outer peripheral length of the cross-section of the void)