SO₂ poisoning of NH₃-SCR catalysts at low temperature (< 300 °C) is still an austere challenge. In this work, γ-Fe₂O₃ was taken as a model catalyst and the effect of reaction temperature on the catalytic activity in the presence of SO₂ were fully revealed. SO₂ introduction has no negative effect on the activity at 300 °C, which gradually improves with the extension of time. While for 225−275 °C, the activity decreases firstly and then increases slowly. The formatted sulfate species inhibits the adsorption of NO_x, cuts off L-H reaction pathway and leads to the initial decline. While the deposited ammonium bisulfate (ABS) can be consumed continuously by NO + O₂, implying the formation and consumption of ABS have reached a dynamic equilibrium. Moreover, the formation of ferric sulfate species results in the enhancement of surface acidity, which leads to the promotion of the E-R reaction pathway and further facilitates the increase of activity.

在低温（<300°C）下NH ₃ -SCR催化剂的SO ₂中毒仍然是严峻的挑战。在这项工作中，γ-的Fe ₂ ö ₃被看作是一个模型的催化剂和反应温度对SO的存在下的催化活性的作用₂进行了充分显现。SO _2的引入对300°C的活性没有负面影响，随着时间的延长逐渐增加。在225-275°C时，活性先下降，然后缓慢上升。格式化的硫酸盐物种抑制NO的吸附_X，切断了LH反应途径并导致了最初的下降。尽管沉积的硫酸氢铵（ABS）可以被NO + O ₂连续消耗，但这意味着ABS的形成和消耗已达到动态平衡。而且，硫酸铁物质的形成导致表面酸度的提高，这导致ER反应途径的促进并且进一步促进了活性的增加。