NH3-SCR activity, hydrothermal stability, sulfur resistance and regeneration of Ce0.75Zr0.25O2–PO43 −catalyst

Ce0.75Zr0.25O2–PO43 − catalyst with high NH3-SCR performance was prepared by impregnating phosphates on Ce0.75Zr0.25O2 synthesized by a sol–gel method. The catalysts were characterized by IR, H2-TPR, NH3 adsorption and activity measurements. Ce0.75Zr0.25O2–PO43 − catalyst shows over 80% NOx conversion at 250–450 °C. The hydrothermal-aged catalyst at 760 °C for 48 h still presents high NH3-SCR performance at 300–400 °C. The sulfur-aged Ce0.75Zr0.25O2–PO43 − catalyst can be regenerated completely by treating catalyst in air at 650 °C. Phosphates improve the ammonia adsorption and decrease the ammonia oxidation on catalyst, leading to a high NH3-SCR activity and a high N2 selectivity of Ce0.75Zr0.25O2–PO43 − catalyst.

Graphical abstractCe0.75Zr0.25O2–PO43 − catalysts with high NH3-SCR deNOx performances in a wide temperature region. Especially, the reported catalyst was found to own ultra-high hydrothermal stability and be feasible to be regenerated at 650 °C after sulfur poisoning.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A Ce0.75Zr0.25O2–PO43 − catalyst shows over 80% NOx conversion at 250–450 °C. ► Catalyst hydrothermal-aged at 760 °C still present high NH3-SCR performances. ► The sulfur-aged catalyst can be regenerated completely by treating in air at 650 °C. ► Phosphate decreases the ammonia oxidation on Ce0.75Zr0.25O2 catalyst.