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

The treatment of NO _x has become an urgent issue due to it being difficult to degrade in air and its tremendous adverse impact on public health. Among numerous NO _x 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 NO _x over Mn-based catalysts with high resistance of SO₂ and H₂O are discussed in detail.