Rationally Fabricated Ce–Mn@ZrO<sub>2</sub>–SO<sub>4</sub><sup>2–</sup> Catalyst Boosts the Efficient Destruction of Chlorobenzene with SO<sub>2</sub> Impurity: Synergy of Surface SO<sub>4</sub><sup>2–</sup> and Acidic Sites
Yukun Sun, Shuai Xu, Bo Bai, Hongna Zhang, Yuliang Li, Guoqiang Gan, Mingjiao Tian, Meng Lan, Zhongshen Zhang, Zhengping Hao, Chi He
Abstract
The catalytic deactivation caused by SO 2 impurity remains a great challenge in the efficient destruction of industrial chlorinated volatile organic compounds (CVOCs). Herein, a Ce–Mn@ZrO 2 –SO 4 2– catalyst with a Ce–O–Mn active system and ZrO 2 –SO 4 2– protective layer was rationally engineered, which exhibits superior activity for chlorobenzene (CB) and SO 2 cotreatment at 228 °C, achieving 90% CB mineralization─over 80% higher than that of the CeO 2 catalyst. In situ characterization and theoretical calculation results reveal that the SO 4 2– groups not only inhibit the adsorption of SO 2 molecules through steric hindrance and electrostatic repulsion but also act as the Brønsted acid sites (BAS) to promote C–Cl cleavage of chlorobenzene (CB) and accelerate the desorption of Cl radicals as inorganic chlorine (HCl and Cl 2 ). Additionally, the Ce–O–Mn structure accelerates electron transfer between active sites, enhances the strength of Lewis acid sites (LAS), and weakens the lattice oxygen stability to generate oxygen vacancies (O v ). These features collectively result in the excellent chlorine and sulfur resistance of the Ce–Mn@ZrO 2 –SO 4 2– catalyst. Compared to CeO 2 and Ce–Mn@ZrO 2, chlorinated and sulfated byproducts respectively decrease by 7.9 and 2.7 times in the presence of 100 ppm SO 2 . This study provides a feasible and promising strategy for engineering efficacious non-noble metal catalysts toward CVOCs’ deep purification with SO 2 impurity, showcasing substantial economic and environmental benefits.