Recent Advances in the Catalytic Oxidation and Degradation of VOCs Using Metal Oxides in Combination with Ozone

This review critically examines recent advances in metal oxide-catalyzed ozonation for the degradation of volatile organic compounds (VOCs) under mild conditions. It clarifies the dual role of ozone in generating surface atomic oxygen and other reactive oxygen species (ROS) through adsorption/decomposition, while replenishing lattice oxygen and oxygen vacancies in Mars-van Krevelen (MvK) redox cycles. The generation and interplay of five ROS (*O, Olat, ·OH, ·O2−, and 1O2) are compared under dry and humid conditions. A five-element framework consisting of active sites, ROS pathways, advantages, limitations, and suitable VOCs is proposed to benchmark noble metal oxides, transition-metal oxides, zeolite-supported catalysts, and single-atom catalysts. Particular attention is given to operando/in situ spectroscopic evidence for ozone adsorption, ROS formation, oxidation of VOCs intermediates, and humidity-induced inhibition, strengthening the mechanistic basis of catalyst evaluation. The humidity effect is described by a volcano-type model, in which moderate water vapor promotes *O-to-·OH conversion, whereas excessive water vapor blocks ozone activation sites. Finally, byproduct formation, catalyst deactivation, regeneration strategies, long-term stability, and standardized testing protocols are discussed to guide practical catalyst design and industrial application.