https://doi.org/10.1016/j.jhazmat.2022.129925

Highlights

• •PVP-stabilized Pt NPs are re-dispersed into single atoms on CeO2 via ex-solution.

• •HSiW chainmail prevents direct exposure of Pt to Cl-contained atmosphere.

• •The formation of dichlorobenzene by-products are avoided with HSiW chainmail.

• •Pollution-free removal of chlorobenzene is reached by HSiW/Pt/CeO2 at below 310 °C.

• •Synergy between HSiW and single-atom Pt on CeO2 is unveiled.

Abstract

Doping noble metal and acid functionalization were both valid approaches to facilitate oxidation of chlorobenzene on CeO2-based catalysts, but their promotion effects were influenced by different orders of modification process. Because of strong interaction between metal and support and proper redox nature of CeO2, Pt NPs were re-dispersed into single atoms on CeO2 surface via “ex-solution”. Companied with Pt loading, the enhancement of oxidizing ability led to generation of polychlorinated by-products. Herein, CeO2-supported Pt was coated by HSiW chainmail to protect Pt from being exposed to Cl-contained atmosphere, and HSiW coating promoted activation of chlorobenzene. The as-prepared chainmail catalyst of HSiW/Pt/CeO2 displayed a remarkable performance in catalyzing oxidation of chlorobenzene without any dichlorobenzene at realistic condition. By comparison, other catalysts with exposed Pt suffered from production of toxic by-products.