Boosted denitration activity of α-Fe2O3 for low-temperature NH3-SCR by addition of Ce/Cu

Abstract

To enhance the low-temperature denitration efficiency of α-Fe₂O₃, Ce/Cu-supported Ce/α-Fe and Cu/α-Fe were synthesized and applied to NH₃-SCR denitration. The findings indicate that Ce and Cu significantly improve the low-temperature denitration performance of α-Fe₂O₃, with the Cu/α-Fe achieving over 95 % catalytic efficiency between 240 and 360 °C. Characterization results show strong interactions and electronic transfer effects between Ce/Cu and Fe, which significantly reduce the crystallinity of α-Fe₂O₃ and generate more surface Fe³⁺ and chemisorbed oxygen. For Cu/α-Fe, its low-temperature denitration performance is largely dependent on its redox capacity and surface acidity. In contrast, the improved low-temperature denitration performance of Ce/α-Fe is mainly attributed to its significantly enhanced surface acidity. Moreover, after loading Ce and Cu, the types of surface adsorbed NO_x species are increased. Particularly for Cu/α-Fe, monodentate nitrate is newly generated, which are key active species for low-temperature catalytic activity, explaining why Cu/α-Fe exhibits the best low-temperature catalytic performance.