An in situ infrared study of NO reduction by C3H8 over Fe-ZSM-5

The interactions of NO, O-2 and NO2 with Fe-ZSM-5, as well as the reduction of NO by C3H8 in the presence of O-2, have been investigated using in situ infrared spectroscopy. The sample of Fe-ZSM-5 (Fe/Al = 0.56) was prepared by solid-state ion exchange. NO adsorption in the absence of O-2 produces o nly mono- and dinitrosyl species associated with Fe2+ cations. Adsorbed NO2 /NO3 species are formed via the reaction of adsorbed O-2 with gas-phase NO or by the adsorption of gas-phase NO2. The reduction of NO in the presence of O-2 begins with the reaction of gas-phase C3H8 with adsorbed NO2/NO3 spe cies to form a nitrogen-containing polymeric species. A reaction pathway is proposed for the catalyzed reduction of NO by C3H8 in the presence of O-2.