| With the implementation of the new national standard,the removal of NOx has become a hot issue,and the removal of NOx in low-temperature flue gas has attracted the attention of many scholars.The current traditional V-based catalysts do not meet the requirements of low-temperature flue gas denitration.Fe-Mn/TiO2 catalysts have the characteristics of good low-temperature denitrification,high stability,and wide active temperature window.However,they are susceptible to the influence of SO2 and H2O.The Fe-Mn/Ti,Fe/Ti,Mn/Ti and Ti catalysts were pre-sulfided at 200℃.The samples before and after presulfidation were characterized by methods of XRD,XPS,TPD,FT-IR,etc.,it reveals that the Fe-Mn/TiO2 catalyst is poisoned by SO2,the main reason is that the adsorpted SO2 on the catalyst is oxidized to SO3 by active center,and then combines with the carrier or NH3 to from the Ti sulfation and the ammonium sulfate on the surface of the catalyst,which result in a decrease de-NOx activity at low-temperature.The Si modifing TiO2 supporting Fe-Mn catalysts,investigated the results revealed that when Ti:Si=7:1,the catalyst had the best sulfur resistance effect.Through characterization by methods of H2-TPR,XRD,FT-IR,NH3-TPD,etc.,it reveals that Si enhances the surface Bronsted acid sites,reduces the valence of active components,and inhibits the adsorption and oxidation of SO2.The sulfur resistance of Fe-Mn/Ti-Si catalysts is improved.The Mo addition in the Fe-Mn/TiO2 catalysts,investigated the results revealed that the catalysts when Mo:Ti=0.04wt%,the catalyst has above 95%denitrification activity at the 200℃and 100 ppm SO2.Through characterization by methods of H2-TPR,SEM,FT-IR,TPD,etc.,it reveals that the addition of Mo could reduce the decomposition temperature of ammonium sulfate,making it difficult for ammonium sulfate to deposit on the surface of the catalyst.The sulfur resistance of 0.04 Mo catalysts is improved.Figure 40;Table 4;Reference 124... |
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