Improvement of SO(2) Resistance of Low-Temperature Mn-Based Denitration Catalysts by Fe Doping

[Image: see text] The influence of vapor and SO(2) in coal firing flue gas on the selective catalytic reduction activity of Mn/γ-Al(2)O(3) and Mn–Fe/γ-Al(2)O(3) catalysts was investigated at 150–275 °C. Denitration experiments and detailed characterization of catalysts were conducted. Vapor had no chemical effects on denitration, and the mechanism of SO(2) deactivating the Mn/γ-Al(2)O(3) catalysts was investigated in detail. This is due to the reaction between MnO(2) and SO(2) and the ammonium sulfate deposits forming on the surface. Sulfation of the Mn-active component was significantly reduced by doping the Mn/γ-Al(2)O(3) catalyst with Fe. Iron doping also lowered the stability of the ammonium sulfate surface deposits, forcing them to rapidly decompose. Thus, iron doping significantly improved SO(2) resistance and the denitration efficiency of Mn–Fe/γ-Al(2)O(3) catalysts was not clearly decreased.