Novel sulfation effect on low-temperature activity enhancement of CeO2-added Sb-V2O5/TiO2 catalyst for NH3-SCR

Abstract Sulfur dioxide (SO 2 ) is considered as a poisoning gas for NH 3 -SCR catalysts under real time conditions. However, it has revealed an obvious beneficial effect on the activity of CeO 2 containing catalysts. Hereby we report the applied research in sulfation effect on low-temperature activity enhancement of CeO 2 -modified, Sb 2 O 3 –V 2 O 5 –TiO 2 catalyst system pretreated with SO 2 under oxidizing conditions at different temperatures for 2 h. We have elucidated the real insights via nature-property relationships of the species formed at various SO 2 pretreatment temperatures ( T  = 300, 400 and 500 °C) with the help of advanced characterization techniques such as X-ray diffraction (XRD), temperature programmed reaction (NH 3 -TPD, NO-TPD and H 2 -TPR), BET surface area, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDS) and X-ray photoelectron spectroscopy (XPS). Our results indicated that SO 2 pre-treatment at 500 °C led to the maximum favorable sulfation with cerium(III) sulfate as the major surface species.