Deeply revealing the mechanism of the synergistic effect of Cu and P on alleviating CaO poisoning performance of V-W-Ti catalysts in cement kilns.

In this work, the redox performance of vanadium-based catalysts was improved by doping copper species, and the phosphorus species was used to combine with CaO to produce Ca(PO 3) 2 , which avoided poisoning and deactivation of the catalysts due to the combination of CaO and vanadium species. In addition, the NH 3 and NO species could be effectively adsorbed and activated on the surface of the Ca-VWCu 3 P 5 Ti catalyst by E-R mechanism. In this way, the harm of CaO to the vanadium-based catalysts was effectively reduced. [Display omitted] • CaO combined with the active sites of the catalyst, resulting in the catalyst poisoning in cement kilns. • Redox property and surface acidity of catalysts were protected by Cu and P doping from CaO. • The phosphorus was used to combine with CaO to form Ca(PO 3) 2 , thus protecting the active sites of vanadium-based catalysts. • After doping with Cu and P, the SCR reaction pathway of the catalyst followed the E-R mechanism. CaO was the inevitable cause of V 2 O 5 -WO 3 -TiO 2 catalyst (VWTi) poisoning in cement kilns. The significant reduction in NO conversion was due to the combination of CaO and active species of the vanadium-based catalyst. In this work, the VWTi catalysts were modified with different contents of Cu and P to improve resistance to CaO, thereby extending the service life of catalysts in cement kilns. By doping Cu and P, the Ca-VWCu 3 P 5 Ti had better catalytic activity, reduced the poisoning effect of CaO to V5+, thus protecting the redox properties and increasing the surface acidic sites of the catalyst. Meanwhile, the in-situ DRIFTs results showed that the poisoning effect of CaO was weaker on the Ca-VWCu 3 P 5 Ti than that of the Ca-VWTi. In addition, the NH 3 and NO species could be effectively adsorbed and activated on the surface of the Ca-VWCu 3 P 5 Ti by E-R mechanism. In this way, the harm of CaO to the vanadium-based catalysts was effectively reduced. This work provided a promising strategy to design vanadium-based catalysts with superior resistance to CaO in NH 3 -SCR reaction. [ABSTRACT FROM AUTHOR]