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SiO₂/V₂O₅/TiO₂ catalysts were synthesized for removing elemental mercury (Hg⁰) from simulated coal-combustion flue gas. Experiments were carried out in fixed-bed reactors using both pellet and powder catalysts. In contrast to the SiO₂−TiO₂ composites developed in previous studies, the V₂O₅ based catalysts do not need ultraviolet light activation and have higher Hg⁰ oxidation efficiencies. For Hg⁰ removal by SiO₂−V₂O₅ catalysts, the optimal V₂O₅ loading was found between 5 and 8%, which may correspond to a maximum coverage of polymeric vanadates on the catalyst surface. Hg⁰ oxidation follows an Eley−Rideal mechanism where HCl, NO, and NO₂ are first adsorbed on the V₂O₅ active sites and then react with gas-phase Hg⁰. HCl, NO, and NO₂ promote Hg oxidation, while SO₂ has an insignificant effect and water vapor inhibits Hg⁰ oxidation. The SiO₂−TiO₂−V₂O₅ catalysts exhibit greater Hg⁰ …