The catalyst bed for exhaust gas purification, making the catalytic converter canning structure for exhaust gas purification, and the exhaust gas purification mannered null silica

摘要

PROBLEM TO BE SOLVED: To provide an exhaust gas purifying catalyst bed capable of efficiently removing NOx in dilute combustion exhaust gas, a catalyst coated structure purifying exhaust gas and a method for purifying NOx in dilute combustion exhaust gas using them. ;SOLUTION: This catalyst A is obtained by adding silica and calcium, and if necessary, adding alumina and/or zirionia. This exhaust purifying catalyst constituted of the catalyst A and a catalyst B composed by adding silver to an alumina carrier having a pore structure wherein Y is 70% or more of X and Z is 20% or less of X when the total value of pore vol. occupying pores with a pore radius is 300 or less is X and the total value of pore vol. occupying process with a pore radius of 25-100 is Y and the total value of pore vol. occupying pores with a core radius of 100-300 is Z in the relation of a pore radius and pore vol.;COPYRIGHT: (C)1998,JPO