Effect of Ce on the acidity of LaMnO3 / Fe2O3 catalyst in NH3-SCR at low temperature

Abstract

Abstract A series of La1 − xCexMnO3/Fe2O3 catalysts were prepared by citric acid method, and their catalytic denitration efficiency and water and sulfur resistance were tested., XRD, BET, H2-TPR, NH3-TPD, XRF, TG and In situ DRIFTS are used to characterize the crystal structure redox properties of the catalysts. The results show that Fe2O3 catalyst loading LaMnO3 can significantly enhance the catalytic denitrification ability of the catalyst at low and medium temperatures. When the doping amount of LaMnO3 is 40%, the catalyst effect is the best, and the maximum efficiency is 94% at 240℃. The optimal temperature activity window is expanded by 30.8% compared with Fe2O3 catalyst at 240℃ to 330℃. The flue gas temperature corresponding to the optimal catalytic denitration efficiency is reduced by 30℃. Ce doping can improve the distribution of active substances on the catalyst surface and further improve the catalytic denitration efficiency at low temperature. La0.6Ce0.4MnO3/Fe2O3 has the highest catalytic denitrification efficiency, reaching the highest efficiency of 96% at 240℃, which is about 4% higher than that of undoped catalyst. In addition, Ce doping significantly weakened the formation of sulfate on the catalyst surface, and La0.6Ce0.4MnO3/Fe2O3 catalyst showed excellent sulfur resistance and water resistance.