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

Abstract

A low-cost goethite and manganese acetate were used to prepare a MnOx/α-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/α-Fe2O3 with Mn/Fe molar ratio of 0.1 and calcination temperature of 400 °C had the best low-temperature catalytic activity and wider reaction temperature window compared with α-Fe2O3. It achieved over 90% NO conversion efficiency with a space velocity of 72,000 h−1 at 200~350 °C and possessed a good resistance of H2O and SO2. Characterization by XRD, BET, H2-TPR, and NH3-TPD revealed that the main reason for the high catalytic activity of MnOx(0.1)/α-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.

Study of the denitration performance of a ceramic filter using a manganese-based catalyst

“…[13][14][15][16] Mn-based catalyst has become the research focus of SCR catalyst due to wider temperature windows and variable valence states. 17,18 Zhou et al 19 discovered MnO x /a-Fe 2 O 3 achieved over 90% NO conversion at 200-350 °C. Wang et al 20 found that the formation of amorphous MnO x had better SCR performance and good resistance to SO 2 and H 2 O. g-Al 2 O 3 is oen used as support catalytic adsorbents because of its ideal pore structure and many hydroxy groups on its surface.…”