The Resistance of SO2 and H2O of Mn-Based Catalysts for NOx Selective Catalytic Reduction with Ammonia: Recent Advances and Perspectives

The treatment of NOx has become an urgent issue due to it being difficult to degrade in air and its tremendous adverse impact on public health. Among numerous NOx emission control technologies, the technology of selective catalytic reduction (SCR) using ammonia (NH3) as the reducing agent (NH3-SCR) is regarded as the most effective and promising technique. However, the development and application of high-efficiency catalysts is severely limited due to the poisoning and deactivation effect by SO2 and H2O vapor in the low-temperature NH3-SCR technology. In this review, recent advances in the catalytic effects from increasing the rate of the activity in low-temperature NH3-SCR by manganese-based catalysts and the stability of resistance to H2O and SO2 during catalytic denitration are reviewed. In addition, the denitration reaction mechanism, metal modification, preparation methods, and structures of the catalyst are highlighted, and the challenges and potential solutions for the design of a catalytic system for degenerating NOx over Mn-based catalysts with high resistance of SO2 and H2O are discussed in detail.