In our previous studies, CuCl₂ demonstrated excellent Hg(0) oxidation capability and holds potential for Hg(0) oxidation in coal-fired power plants. In this study, the properties and performances of CuCl₂ supported onto γ-Al₂O₃ with high surface area were investigated. From various characterization techniques using XPS, XAFS, XRD, TPR, SEM and TGA, the existence of multiple copper species was identified. At low CuCl₂ loadings, CuCl₂ forms copper aluminate species with γ-Al₂O₃ and is inactive for Hg(0) oxidation. At high loadings, amorphous CuCl₂ forms onto the γ-Al₂O₃ surface, working as a redox catalyst for Hg(0) oxidation by consuming Cl to be converted into CuCl and then being regenerated back into CuCl₂ in the presence of O₂ and HCl gases. The 10%(wt) CuCl₂/γ-Al₂O₃ catalyst showed excellent Hg(0) oxidation performance and SO₂ resistance at 140 °C under simulated flue gas conditions containing 6%(v) O₂ and 10 ppmv HCl. The oxidized Hg(0) in the form of HgCl₂ has a high solubility in water and can be easily captured by other air pollution control systems such as wet scrubbers in coal-fired power plants. The CuCl₂/γ-Al₂O₃ catalyst can be used as a low temperature Hg(0) oxidation catalyst.