Rationally Fabricated Ce-Mn@ZrO2-SO42- Catalyst Boosts the Efficient Destruction of Chlorobenzene with SO2 Impurity: Synergy of Surface SO42- and Acidic Sites.

The catalytic deactivation caused by SO2 impurity remains a great challenge in the efficient destruction of industrial chlorinated volatile organic compounds (CVOCs). Herein, a Ce-Mn@ZrO2-SO42- catalyst with a Ce-O-Mn active system and ZrO2-SO42- protective layer was rationally engineered, which exhibits superior activity for chlorobenzene (CB) and SO2 cotreatment at 228 °C, achieving 90% CB mineralization─over 80% higher than that of the CeO2 catalyst. In situ characterization and theoretical calculation results reveal that the SO42- groups not only inhibit the adsorption of SO2 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 Cl2). 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 (Ov). These features collectively result in the excellent chlorine and sulfur resistance of the Ce-Mn@ZrO2-SO42- catalyst. Compared to CeO2 and Ce-Mn@ZrO2, chlorinated and sulfated byproducts respectively decrease by 7.9 and 2.7 times in the presence of 100 ppm SO2. This study provides a feasible and promising strategy for engineering efficacious non-noble metal catalysts toward CVOCs' deep purification with SO2 impurity, showcasing substantial economic and environmental benefits.