Preparation and optimization of Mn-based catalysts for low-temperature NH3-SCR: Component selection, synthesis strategy and influencing factors

Mn-based catalysts have attracted more and more attention in the past decade due to their excellent lowtemperature NH3-selective catalytic reduction activity (150-225 degrees C). However, it also has weak H2O&SO2 resistance, which has become the focus of research in recent years. Advancements in techniques such as element doping, carrier selection and preparation optimization can improve the surface acidity and redox capacity of these catalysts, thereby enhancing their H2O&SO2 resistance. This paper reviews the active components, carriers, synthesis methods and the factors affecting the catalytic performance (activity and stability) of low-temperature selective catalytic reduction denitrification catalysts. The optimization methods for active components and metal doping are discussed and the current research status of carriers (such as TiO2, Al2O3, CeO2, activated carbon and carbon nanotubes) are reviewed. Additionally, common synthesis methods are summarized, including mechanical mixing, impregnation, deposition-precipitation, sol-gel and hydrothermal synthesis. The paper focuses on how the factors (such as precursor type, ratio of elements doping, pH of precursor solution, loading of active components and calcination conditions) impact the denitrification activity and stability of catalysts. Finally, the progress and shortcomings in current research on NH3-SCR catalysts are summarized, and future research should focus on developing active protective components with sulfur release capacities, enhancing resistance to multiple poisoning factors under complex conditions and achieving multi-pollutant synergistic treatment.