A Review of Simultaneous Catalytic Removal of NOx and VOCs: From Mechanism to Modification Strategy

Simultaneous catalytic elimination of nitrogen oxides (NOx) and volatile organic compounds (VOCs) represents a promising technology for addressing the synergistic pollution of fine particulate matters of <2.5 μm diameter (PM2.5) and O3. Nevertheless, it has been maintaining significant challenges in practical implementation, particularly the inherent mismatch in temperature windows between NOx reduction and VOCs oxidation pathways, coupled with catalyst poisoning and deactivation phenomena. These limitations have hindered the industrial application of bifunctional catalysts for the removal of concurrent pollutant. This review systematically explored the fundamental mechanisms and functional roles of active sites in controlling synchronous catalytic processes. The mechanism of catalyst deactivation caused by multiple toxic substances has been comprehensively analyzed, including sulfur dioxide (SO2), water vapor (H2O), chlorine-containing species (Cl*), reaction by-products, and heavy metal contaminants. Furthermore, we critically evaluated the strategies of doping regulation, nanostructure engineering and morphology optimization to enhance the performance and toxicity resistance of catalysts. Meanwhile, emerging regeneration techniques and reactor design optimizations are discussed as potential solutions to improve the durability of catalysts. Based on the above critical aspects, this review aims to provide insights and guidelines for developing robust catalytic systems capable of controlling multi-pollutants in practical applications, and to offer theoretical guidance and technical solutions to bridge the gap between laboratory research and industrial environmental governance applications.