This paper discussed a recent study of elemental mercury removal by gaseous hydrogen chloride over novel CeO 2–WO 3/TiO 2 catalysts under bench scale conditions. The performances of mercury removal over the catalysts were tested in simulated flue gas with 80–100 μg m −3 Hg 0, 8% O 2, 10 ppm HCl, 8% H 2O, 800 ppm SO 2 and balanced with N 2. Results indicated that about 95% of the Hg 0 could be removed by hydrogen chloride over the CeO 2–WO 3/TiO 2 catalysts in the presence of O 2, and the HgO that formed was effectively converted to mercury chloride when hydrogen chloride was added to the system. The Hg 0 removal efficiency was found to be slightly but significantly affected by H 2O and SO 2 addition. Water vapor slightly inhibited the Hg 0 removal efficiency, due to the competitive adsorption. By contrast, SO 2 promoted the oxidation reactions, resulting in higher Hg 0 removal efficiencies. The Hg-TPD and SO 2-TPD results indicated that less negative effect of Hg adsorption with/without water vapor and less adsorption mass of SO 2 might be responsible for the tolerance of the catalysts to H 2O and SO 2. From the characterization results, the BET surface areas had no significant influence on the catalytic performance. The XRD pattern indicated that cubic CeO 2 crystallite was the crystalline form on the surface. The XPS and H 2-TPR results suggested that Ce 4+ oxide was the main form of Ce on the catalysts surfaces, which was beneficial for the Hg 0 removal reactions.