Recent advances in the design and application of modified ZSM-5 catalysts for gaseous pollutant oxidation

Gaseous pollutants pose serious environmental and human health risks because of their toxicity, persistence, and complex emission characteristics. Among the available abatement technologies, catalytic oxidation is considered an effective route because it can convert hazardous pollutants into less harmful products under relatively mild conditions. As a representative zeolitic material, ZSM-5 has been widely investigated for gaseous pollutant oxidation owing to its tunable acidity, shape-selective framework, and high thermal stability. However, pristine ZSM-5 is often limited by insufficient redox functionality, diffusion constraints, and poor tolerance to realistic reaction environments, making structural and compositional modification essential for practical applications. This review summarizes recent advances in modified ZSM-5 catalysts for gaseous pollutant oxidation. Four major modification strategies, including metal modification, core-shell construction, hydrothermal treatment, and alkali treatment, are discussed. The oxidation performance of modified ZSM-5 toward different gaseous pollutants is then examined together with the corresponding reaction mechanisms. Particular attention is given to the roles of catalyst properties, such as Si/Al ratio, acid sites, and pore structure, as well as reaction conditions, including H₂O, sulfur-containing species, ozone, and chlorine-containing compounds, in governing catalytic performance and deactivation. By integrating modification strategies, catalyst properties, oxidation behavior, and reaction pathways, this review reveals the key relationships among performance, mechanisms, and reaction conditions in modified ZSM-5 catalysts, provides important guidance for the rational design of efficient and durable ZSM-5-based oxidation catalysts, and outlines the critical scientific challenges and future directions in this field.