INTRAPORE CATALYSIS IN NO REDUCTION WITH METHANE ON IR IN/H-ZSM-5 CATALYST/

Chemisorption of NOx on In/H-ZSM-5, Ir/In/H-ZSM-5, and the physical mi xture of Ir/H-ZSM-5 and In/H-ZSM-5, and the catalytic activities of th ese catalysts for NO reduction with methane are studied to understand the role of Ir onto In/H-ZSM-5. The amount of NOx chemisorption on Ir/ In/H-ZSM-5 was largest among the catalysts tested. The catalytic activ ities for NOx reduction on these catalysts were well correlated to the amount of chemisorbed NOx. The dual-functional mechanism, that is, NO oxidation and NO2 reduction with CH4 works effectively on Ir and [InO ](+) sites, respectively, in the same zeolite pore, as an intrapore ca talysis.