Promoting C–Cl Bond Activation via a Preoccupied Anchoring Strategy on Vanadia-Based Catalysts for Multi-Pollutant Control of NO<sub>x</sub> and Chlorinated Aromatics
Xing Yuan, Yu Wang, Xiao Zhu, Bin Zhou, Zijian Song, Zhen Chen, Yue Peng, Wenzhe Si, Junhua Li
Abstract
Regulating vanadia-based oxides has been widely utilized for fabricating effective difunctional catalysts for the simultaneous elimination of NO x and chlorobenzene (CB). However, the notorious accumulation of polychlorinated species and excessively strong NH 3 adsorption on the catalysts lead to the deterioration of multipollutant control (MPC) activity. Herein, protonated sulfate (−HSO 4 ) supported on vanadium-titanium catalysts via a preoccupied anchoring strategy are designed to prevent polychlorinated species and alleviate NH 3 adsorption for the multipollutant control. The obtained catalysts with −HSO 4 modification achieve an excellent NO x and CB conversion with turnover frequency values of ∼ 3.63 and 17.7 times higher than those of the pristine, respectively. The protonated sulfate promotes the formation of polymeric vanadyl with a higher chemical state and d-band center of V. The modulated catalysts not only substantially alleviate the competitive adsorption of multipollutant via the “V 3d–O 2p–S 3p” network, but also distinctly strengthen the Brønsted acid sites. Besides, the introduced proton donor of the −HSO 4 connecting polymeric structure could markedly reduce the reaction barrier of breaking the C–Cl bond. This work paves an advanced way for low-loading vanadium SCR catalysts to achieve highly efficient NO x and CB oxidation at a low temperature.