Research of SO_2 resistance of MnO_x catalyst modified by Ce for low temperature SCR with NH_3

摘要

Two catalysts, MnO_x and ceria modified MnO_x were prepared by deposition-precipitation method and used for low-temperature selective catalytic reduction (SCR) with NH_3 in the presence of SO_2. The catalysts were characterized by X-ray diffraction (XRD), surface area measurement (BET) and thermal gravimetry analysis(TG). The deactivation of MnO_x and MnO_x-CeO_2 by SO_2 was observed during SCR process. It was found that the resistance to SO_2 could be greatly enhanced for Ce modified MnO_x. It was because that the formation of Mn(SO_4)_x was prevented and the depositions of (NH_4)_2_SO_4 and NH_4HSO_4 were significantly inhibited with the doping of ceria.