Selective reduction of nitric oxide by methane on H-form zeolite catalysts in oxygen-rich atmosphere

Abstract

Selective reduction of NO by CH4 in the presence of excess oxygen was investigated using H-form zeolite catalysts. H-ZSM-5, H-ferrierite, and H-mordenite showed high catalytic activity and selectivity. On the contrary, H-USY and Al2O3 were not effective for this reaction. Both NO-CH4 and O2-CH4 reaction hardly proceeded on H-ZSM-5. Higher NOx conversion was obtained in the NO2-O2-CH4 and NO2-CH4 systems than in the NO-O2-CH4 system under high GHSV condition. It seemed that NO2 plays an important role for selective reduction of NO by CH4 on H-form zeolites.