Chemical deactivation and resistance of Mn-based SCR catalysts for NOx removal from stationary sources

As a high-performance technology currently developed, selective catalytic reduction (SCR) of NOx with NH3 has been universally employed to remove NOx from stationary sources. The traditional applied V2O5-based catalysts are proverbially applicable for medium-temperature range but unsuitable for NH3-SCR operated in the low-temperature conditions. Through massive research of theory and experiments, low-temperature NH3-SCR has drawn substantial attention due to the extensive demand for industrial furnaces and their energy-saving characteristics. During the past few years, Mn-based catalysts have been extensively investigated in NH3-SCR reaction for their high catalytic activity at low temperatures. In this paper, the deactivation mechanisms of SO2, H2O, alkali/alkaline earth metals (K, Na, Ca), and heavy metals (As, Pb, etc.) over Mn-based catalysts are discussed in detail. This review summarizes the methods to improve the anti poisoning of manganese-based catalysts, such as specific preparation methods, adding active components, doping additions and carrier modification, etc. Finally, different regeneration methods of poisoning caused by various poisons were analyzed and compared The obtained results can help researchers provide insight into the optimization of Mn-based SCR catalysts.