Environmental catalysis for NOx reduction faces significant challenges due to the evolving energy landscape and complex operating conditions in non-electric sectors and mobile sources. Traditional NH3-SCR catalysts, such as V2O5-WO3/TiO2 and chabazite (CHA) zeolites, struggle to meet the demands of high activity at low temperatures and resistance to various poisons like SO2, HCl, and heavy metals. Additionally, VOCs coexisting with NOx in exhaust gases further complicate efficient NOx reduction. To address these challenges, the strategic manipulation of surface acidity and redox properties of NH3-SCR catalysts is crucial for enhancing catalytic efficiency at low temperatures. Protective sites and confined structures, along with strategies to trigger antagonistic effects, are essential for improving antipoisoning capabilities. Selective synergistic catalytic elimination technology is vital for effectively reducing both NOx and VOCs. Recent advancements in catalysts have focused on modulating supported components and structural properties to enhance low-temperature activity and antipoisoning performance. For instance, metal oxides like MnO2, CeO2, and SmO2 play key roles in redox sites, while acidic metal oxides supply Lewis and Bronsted acid sites. The Cu-SSZ-13 catalyst, widely used for mobile source exhaust purification, faces challenges related to cold-start emissions and catalyst poisoning by alkali metals and heavy metals. Strategies such as secondary ionic modification of Cu-exchanged molecular sieves have been shown to improve hydrothermal stability and low-temperature performance. The development of novel catalysts with enhanced low-temperature activity and antipoisoning ability is critical for advancing environmental catalysis technology. The reaction mechanisms of NH3-SCR involve both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms, with the latter being more relevant at low temperatures. The rate-determining step varies with temperature and reaction conditions, necessitating strategies to reduce the energy barrier of the reaction. Overall, the focus remains on optimizing active sites, reaction pathways, and catalyst structures to achieve efficient NOx reduction in diverse applications.Environmental catalysis for NOx reduction faces significant challenges due to the evolving energy landscape and complex operating conditions in non-electric sectors and mobile sources. Traditional NH3-SCR catalysts, such as V2O5-WO3/TiO2 and chabazite (CHA) zeolites, struggle to meet the demands of high activity at low temperatures and resistance to various poisons like SO2, HCl, and heavy metals. Additionally, VOCs coexisting with NOx in exhaust gases further complicate efficient NOx reduction. To address these challenges, the strategic manipulation of surface acidity and redox properties of NH3-SCR catalysts is crucial for enhancing catalytic efficiency at low temperatures. Protective sites and confined structures, along with strategies to trigger antagonistic effects, are essential for improving antipoisoning capabilities. Selective synergistic catalytic elimination technology is vital for effectively reducing both NOx and VOCs. Recent advancements in catalysts have focused on modulating supported components and structural properties to enhance low-temperature activity and antipoisoning performance. For instance, metal oxides like MnO2, CeO2, and SmO2 play key roles in redox sites, while acidic metal oxides supply Lewis and Bronsted acid sites. The Cu-SSZ-13 catalyst, widely used for mobile source exhaust purification, faces challenges related to cold-start emissions and catalyst poisoning by alkali metals and heavy metals. Strategies such as secondary ionic modification of Cu-exchanged molecular sieves have been shown to improve hydrothermal stability and low-temperature performance. The development of novel catalysts with enhanced low-temperature activity and antipoisoning ability is critical for advancing environmental catalysis technology. The reaction mechanisms of NH3-SCR involve both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms, with the latter being more relevant at low temperatures. The rate-determining step varies with temperature and reaction conditions, necessitating strategies to reduce the energy barrier of the reaction. Overall, the focus remains on optimizing active sites, reaction pathways, and catalyst structures to achieve efficient NOx reduction in diverse applications.