Recent advances in catalytic oxidation of chlorobenzene over metal oxide-based catalysts

The emission of chlorinated volatile organic compounds (Cl-VOCs) is a significant contributor to air pollution, impacting both the environment and human health. Chlorobenzene, with typical characteristics of Cl-VOCs, is often used as a representative compound in research owing to its widespread presence in various industrial processes such as fine chemical engineering and coking. Catalytic oxidation has emerged as an effective technology for removing chlorobenzene from waste gases. Metal oxides such as MnOx, CoOx, CeOx, FeOx, CuOx, and VOx have garnered attention for their potential as active species and additives in chlorobenzene oxidation, offering advantages such as earth abundance, ease of fabrication, and relatively low cost. This review provides a comprehensive overview of recent advancements in the catalytic oxidation of chlorobenzene using metal oxide-based catalysts. Key properties such as activity, selectivity, stability, and adaptability to flue gas components are considered crucial for evaluating these catalysts. The review systematically examines the progress made in enhancing these properties. Given the generation of various byproducts and the presence of diverse flue gas components such as Hg0, NOx, and other VOCs, strategies for improving CO2 selectivity, adaptability to flue gas components, and overall stability of the catalysts are discussed. Mechanisms underlying chlorobenzene degradation are also elucidated from a microscopic perspective. Finally, the review emphasizes the need for designing and developing new catalysts capable of achieving stable, long-term performance in real-world flue gases to effectively reduce VOC emissions.