Understanding the Role of Surface Oxygen in Hg Removal on Un-Doped and Mn/Fe-Doped CeO2(111) |
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| Authors: | Ping Liu Lixia Ling Hao Lin Baojun Wang |
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| Affiliation: | 1. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001 People's Republic of China;2. College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, 030024 People's Republic of China;3. Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan, 030024 People's Republic of China |
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| Abstract: | Effects of surface-adsorbed O and lattice O for the CeO2(111) surface on Hg removal has been researched. In this work, periodic calculations based on density functional theory (DFT) were performed with the on-site Coulomb interaction. Hg is oxidized to HgO via the surface-adsorbed O by overcoming a Gibbs free energy barrier of 114.1 kJ·mol−1 on the CeO2(111) surface. Mn and Fe doping reduce the activation Gibbs free energy for the Hg oxidation, and energies of 70.7 and 49.6 kJ·mol−1 are needed on Ce0.96Mn0.04O2(111) and Ce0.96Fe0.04O2(111) surfaces. Additionally, lattice O also plays an important role in Hg removal. Hg cannot be oxidized leading to the formation of HgO on the un-doped CeO2(111) surface owing to the inertness of lattice O, which can be easily oxidized to HgO on Ce0.96Mn0.04O2(111) and Ce0.96Fe0.04O2(111) surfaces. It can be seen that both surface-adsorbed O and lattice O play important roles in removing Hg. The present study will shed light on understanding and developing Hg removal technology on un-doped and Mn/Fe-doped CeO2(111) catalysts. © 2019 Wiley Periodicals, Inc. |
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| Keywords: | lattice O Mn/Fe doping Hg removal density functional theory surface-adsorbed O |
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