Selective catalytic reduction of NO by propane in excess oxygen over IrCu-ZSM-5 catalyst

The selective reduction of NO by propane over bimetallic IrCu-ZSM-5 was investigated in this study. IrCu-ZSM-5, together with Cu-ZSM-5 and Ir-ZSM-5, was characterized by FTIR of pyridine adsorption, UV–vis spectroscopy and H2-TPR. The results indicated that the nature of Cu species changed with iridium as a modifier. The reaction mechanism over IrCu-ZSM-5 was investigated using in situ DRIFT spectra and nitrate species were observed as the main reaction intermediate for NO reduction by propane. The addition of trace iridium into Cu-ZSM-5 favored the formation of nitrate species, and thus better catalytic activity could be obtained on IrCu-ZSM-5.