Preparation of Ce-Zr-O_x/ATS composite catalyst and its catalytic oxidation of Hg⁰

A series of Ce-Zr-O_x/ATS composite catalysts are prepared by isometric impregnation method. Ce-Zr-O_x/ATS catalyst is employed on the catalytic oxidation of Hg⁰ in the presence of hydrogen chloride. Results show that Hg⁰ oxidation efficiency maintains over 80% (space velocity: 7000 h^-1) in the range of 200~350℃. While the reaction temperature is 350℃, O₂ content is 6%, and HCl content is 20 mg·m^-3, the Hg⁰ oxidation efficiency reaches 94.7%. N₂ adsorption results show that the specific surface area, pore volume and pore size of the catalyst are not correlated with mercury removal capacity. It is found that SO₂ inhibits Hg⁰ removal reaction because of the competitive adsorption of SO₂ and HCl in the active sites on the surface of the catalyst. NH₃ also has the same inhibiting effect due to the competitive adsorption of NH₃ and Hg⁰.