NOx reduction against alkali poisoning over Ce(SO4)2-V2O5 /TiO2 catalysts by constructing the Ce4+-SO42-pair sites

Commercial V2O5 -based catalysts have been successfully applied in NH3 selective catalytic reduction (NH3 -SCR) of NOx from power stations, but their poor alkali -resistance restrains the wider application in nonelectrical industries. In this study, NOx reduction against alkali poisoning over V2O5/TiO2 is greatly improved via Ce(SO4)2 modification. It has been originally demonstrated that Ce4 + -SO42- pair sites play crucial roles in improving NOx reduction against alkali poisoning over V2O5/TiO2 catalysts. The strong interaction between V species and Ce sites of Ce4 + -SO42- pairs triggers the reaction between NH4 + species and gaseous NO via Eley-Rideal (E -R) reaction pathway. After K -poisoning, the SO42- sites of Ce4 + -SO4 2- pairs as protective sites strongly bond with K and thus maintain the high reaction efficiency via the E -R reaction pathway. This work demonstrates an effective strategy to enhance NOx reduction against alkali poisoning over catalysts via constructing Ce4 + -SO42- pair sites, contributing to developing alkali -resistant SCR catalysts for practical application in nonelectrical industries. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.