Designing VWTi-based catalysts with K resistance via Ce-S modification for selective catalytic reduction of NOx

Selective catalytic reduction (SCR) with NH3 is the main reaction to eliminate nitrogen oxide, and the access of K+ to the catalyst surface severely deactivates the physicochemical properties. To inhibit the deactivation of the catalyst by potassium (K), we synthesized VWCeSTi. In the current study, the catalyst surface was functionalized with cerium sulfate (Ce-S) as a method to suppress K+ deactivation, and the physicochemical properties of the functionalized catalyst were explored. In VWCeSTi, Ce has a low electronegativity compared with V and W; hence, sulfated Ce has a relatively abundant electronic state. Therefore, the approach of the K+ ion in an electron-deficient state leads to the preferential binding of S with K, forming K2SO4 and inhibiting chemical deactivation. Additionally, the addition of Ce-S resulted in improved NH3 adsorption ability, the amount of defective metal species, and participating oxygen. Thus, the modified (Ce-S) catalyst showed improved SCR performance and increased resistance to K.