Mechanisms of Elemental Mercury Transformation on α-Fe2O3(001) Surface from Experimental and Theoretical Study: Influences of HCl, O2, and SO2

详细信息    查看全文

• 作者：Ting Liu ; Lucheng Xue ; Xin GuoJia Liu ; Yu Huang ; Chuguang Zheng
• 刊名：Environmental Science & Technology
• 出版年：2016
• 出版时间：December 20, 2016
• 年：2016
• 卷：50
• 期：24
• 页码：13585-13591
• 全文大小：540K
• ISSN：1520-5851

文摘

The reaction mechanisms of a mixture gas of HCl, O₂, and SO₂ in Hg⁰ adsorption on α-Fe₂O₃(001) surface are clarified by a group of adsorption experiments and theoretical calculations based on the density functional theory. The role of O₂ in removing Hg⁰ is greatly influenced by the reaction temperature, meanwhile, the O atom coverage could affect the adsorption performance of Hg⁰. The dissociated O₂ competes with the active sites of Cl species on Fe surface at low temperature, however, at medium temperature HCl and O₂ could simultaneously facilitate the Hg⁰ transformation. Combined with the theoretical calculations, the role of SO₂ and the probable pathways in removing Hg⁰ are discussed. Lower concentration of SO₂ as well as HCl could dissociate on α-Fe₂O₃(001) surface, and the intermediates combine with gaseous Hg⁰, forming mercury–sulfur, mercury–chlorine compounds, and so forth. In addition, the different concentrations of SO₂ are also discussed, and the corresponding X-ray photoelectron spectroscopy analysis on contrasted samples is conducted to research the morphological characterization, providing a reliable basis for judging the probable pathways of Hg⁰ transformation.