Advances in the catalytic oxidation of chlorinated volatile organic compounds: catalyst design, chlorine resistance, byproduct suppression, and mechanistic insights.

Industrial emissions of chlorinated volatile organic compounds (CVOCs) severely threaten human health and ecosystems. While catalytic oxidation provides an efficient and eco-friendly alternative to costly traditional remediation methods, its practical application faces critical bottlenecks. Free chlorine species generated during C-Cl bond cleavage strongly chemisorb onto active sites, inducing rapid catalyst deactivation via chlorine poisoning. A fundamental trade-off between catalyst oxidation capacity and HCl selectivity simultaneously drives the uncontrollable formation of highly toxic byproducts, including Cl2, polychlorinated aromatics, polychlorinated biphenyls, and dioxins. Compounding these issues are competitive side reactions such as the Deacon reaction and nucleophilic or electrophilic substitutions, which demand precise control over complex intermediate transformations. Recognizing the absence of comprehensive literature addressing these interconnected mechanisms, this review delivers a holistic analysis of current catalytic oxidation technologies. We critically examine the structure-activity relationships and anti-poisoning properties of noble metal, non-noble metal, and metal-organic framework-derived porous catalysts. The discussion elucidates multi-pathway reaction systems, chlorinated intermediate transformation rules, and specific HCl generation mechanisms. By integrating structure-activity insights with complex chlorine migration dynamics, this work identifies prevailing challenges and outlines future research trajectories, establishing a robust theoretical foundation for designing advanced catalytic materials.