Mn/TiO2 (MT), Ce/TiO2 (CT) and Ce-Mn/TiO2 (CMT) sorbents for mercury removal were prepared by the impregnation method. Mercury adsorption experiments were conducted on a fixed-bed reactor. The mercury removal performance of the three sorbents gradually increased with the increase of temperature in the range of 100~200℃. The maximum mercury capture efficiency of 91%, 58% and 95% were observed at 200℃ for MT, CT and CMT, respectively. The mercury removal efficiency decreased when the temperature was higher than 200℃. When MT and CT sorbents were exposed in the flue gas with N2+6%O2+1000×10-6SO2, the decrease of mercury removal efficiency to 50% within 30min was observed, indicating the weak SO2resistance of MT and CT. However, mercury removal efficiency of more than 80% was maintained by CMT within 2h. It revealed that Ce doping in MT not only improved the mercury removal performance, but also enhanced the SO2resistance. Physicochemical characteristics of the sorbents were analyzed by N2adsorption/desorption, X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The spent sorbents were analyzed by thermogravimetric analysis (TG) and temperature programmed desorption (TPD) experiments. Based on the experimental and characterization results, the mechanism of SO2resistance of the CMT for mercury removal was interpreted. The doping of Ce improved the dispersion of active components on the sorbent surface and the ratio of Mn4+, which was favorable for mercury removal; Compared with MnO2, CeO2preferentially react with SO2, which inhibited the toxic effect on Mn4+, thus improving the SO2resistance.
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