Non-Noble Metal Catalyst Design with Dual Oxygen–Chlorine Channels: Synergistic Cr–Zr Doping in Ceria for Complete Chlorobenzene Oxidation and Polychlorinated Byproduct Inhibition

The development of efficient catalysts for chlorinated volatile organic compound (CVOC) abatement remains challenging due to insufficient low-temperature activity, chlorine poisoning susceptibility, and toxic byproduct formation. This study addresses these limitations through rational design of Cr-Zr codoped ceria catalysts for efficient, stable, and low-toxic degradation of chlorobenzene (CB). The optimized (CeCr)₃Zr₁ catalyst demonstrates exceptional performance, maintaining >90% CB conversion over 24 h at 240 °C with minimal polychlorinated byproducts. Structure-performance mechanistic investigations reveal that Cr-Zr doping modulates Ce-O bond strength and generates high-density oxygen vacancies, enhancing lattice oxygen mobility and reactive oxygen species generation for deep oxidation. Concurrent Zr incorporation introduces Brønsted acid sites that promote HCl formation via proton-assisted Cl removal, effectively suppressing electrophilic chlorination of aromatic intermediates. These improvements of dual oxygen-chlorine channels reduce the occurrence of electrophilic chlorination reactions in intermediate products, thereby inhibiting the formation of polychlorinated byproducts, making it more promising for industrial applications.