The enhancement for SCR of NO by NH3 over the H2 or CO pretreated Ag/γ-Al2O3 catalyst

Abstract

H₂ or CO pretreatment had been processed on the Ag/γ-Al₂O₃ catalyst which significantly enhanced its NH₃-SCR activity. The main purpose of this study was to prove that the impacts of pretreatment on silver species caused the enhancement. XRD, UV-vis, XPS, in situ FTIR and NO-TPD results showed the relationship between pretreatment, Ag species, NO_X adsorption and NO_X conversion. Extra nitrates were adsorbed on the Ag clusters which were produced by the pretreatment, thereby enhancing the activity. The reactivities between NO and NH₃ had been studied. The difference between CO-pretreatment and H₂-pretreatment had also been discussed. Furthermore, the durability and stability of the pretreated sample were tested. Therefore, a modified Ag₂O/Al₂O₃ catalyst for NH₃-SCR was researched.