Enhancing SO2 resistance in vanadium catalysts with tungsten disulfide for NH3-SCR

• WS 2 introduced as a novel promoter for the selective catalytic reduction of NH 3. • SO 2 adsorption on V-based catalysts suppressed via the sulfur layer of WS 2 . • Hydrogen annealing used to increase active sites on the basal plane of WS 2 . • Low-temperature activity and SO 2 tolerance improved without altering commercial synthesis. • VWS 2 /Ti catalyst maintained the NH 3 adsorption and catalytic activity in the presence of SO 2 . NO x emissions are a major environmental issue, and NH 3 -SCR is a key method for their control. V-based catalysts perform well at high temperatures; however, SO 2 -poisoning remains a critical issue for NH 3 -SCR catalysts under low-temperature conditions. In this study, we develop an effective strategy of loading a stable sulfide two-dimensional (2D) material, WS 2 , to enhance the SO 2 resistance of existing commercial V/Ti catalysts. In-situ DRIFTS analysis and spent SO 2 -poisoning catalyst analyses are conducted to clarify the enhanced SO 2 resistance mechanism. These findings demonstrate that the superior SO 2 resistance can be attributed to the suppression of SO 2 by WS 2 . Therefore, WS 2 loading inhibits the SO 2 adsorption and protects the NH 3 species adsorption, thereby enhancing the SO 2 resistance and low-temperature activity. This research can be utilized without changing the catalyst synthesis process, allowing it to be applied to current commercial catalysts, thereby underscoring its remarkable potential for industrial applications.