Durability of Cu/SAPO-34 catalyst for NOx reduction by ammonia: Potassium and sulfur poisoning

• Cu/SAPO-34 owns much higher alkali poisoning resistance than V2O5/WO3–TiO2 catalyst.
• K-impregnation affects active copper sites slightly due to pore structure of zeolite.
• The formation of copper sulfates deactivates the catalyst at low temperatures.
• Both the poisoned catalysts show higher NH3-SCR activities at high temperatures.

Cu/SAPO-34 catalyst prepared by a wetness impregnation method shows better low-temperature NH3-SCR performance and higher alkali poisoning resistance than V2O5/WO3–TiO2 catalyst, but it exhibits a weaker resistance to sulfur dioxide. Both the poisoning treatments improve the high-temperature NOx conversion but decrease the low-temperature performance of Cu/SAPO-34. The textural properties and surface acidity are affected by the poisoning treatments to some extent. Nevertheless, the reducibility of copper species is suggested to be a more important factor to determine the deNOx performance of the catalysts.

The effects of poisoning treatment on Cu/SAPO-34 synthesized by a wetness impregnation method improve the high-temperature activity and decrease the low-temperature activity.Figure optionsDownload as PowerPoint slide