Abstract: In order to improve the adsorption efficiency of adsorbent for removal of Hg⁰ in flue gas, the sorbent of FeCl₃@MIL-101(Cr) is prepared by impregnating metal organic frameworks (MOFs) materials with FeCl₃ solution for modification. The MOFs material possesses well-developed pore structure and high specific surface area (1997.0100 m²/g). The effects of the impregnation concentration, reaction temperature and oxygen content for removal of Hg⁰ were investigated on a small fixed bed reactor. It was found that the maximum adsorption breakthrough time of Hg⁰ was 62 h, and the corresponding adsorption capacity was 14.27 mg/g, when the FeCl₃ impregnation concentration was 0.2 mol/L, the reaction temperature was 60℃, the carrier gas flow rate was 400 mL/min, the impregnation temperature was 115℃ and the oxygen content was 1%. The physical and chemical characteristics of the adsorbent before and after modification were further studied by using Brunauer-Emmett-Teller (BET), Scanning Electronic Microscopy (SEM)-Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was proved that the adsorption of Hg⁰ by modified MOFs materials is the result of the interaction between physical adsorption and chemical adsorption. What is more, the chlorine functional group has also played a considerable role in Hg⁰ adsorption, and oxygen can promote the adsorption effect. The mechanism of adsorption was analyzed lastly. The experimental results show that the adsorbents have excellent performance of mercury removal at low temperatures and present great application prospects.