Effect of MnOx/α-Fe2O3 Prepared from Goethite on Selective Catalytic Reduction of NO with NH3

摘要

A low-cost goethite and manganese acetate were used to prepare a MnOx/alpha-Fe2O3 composite catalyst by simple impregnation method for novel high-efficiency selective catalytic reduction (SCR) of NO with NH3, and its denitration performance of composite catalyst under different conditions was investigated in a thermal fixed-bed catalytic reaction system. The results showed that MnOx/alpha-Fe2O3 with Mn/Fe molar ratio of 0.1 and calcination temperature of 400 degrees C had the best low-temperature catalytic activity and wider reaction temperature window compared with alpha-Fe2O3. It achieved over 90% NO conversion efficiency with a space velocity of 72,000 h(-1) at 200~350 degrees C and possessed a good resistance of H2O and SO2. Characterization by XRD, BET, H-2-TPR, and NH3-TPD revealed that the main reason for the high catalytic activity of MnOx(0.1)/alpha-Fe2O3(400) was that the addition of Mn changed phase types of catalyst and valence composition of Fe, resulting in a larger specific surface area, more acidic sites, and higher redox performance.

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