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Understanding the Role of Surface Oxygen in Hg Removal on Un‐Doped and Mn/Fe‐Doped CeO 2 (111)
Author(s) -
Liu Ping,
Ling Lixia,
Lin Hao,
Wang Baojun
Publication year - 2019
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.26038
Subject(s) - doping , adsorption , density functional theory , chemistry , lattice energy , oxygen , gibbs free energy , catalysis , lattice (music) , inorganic chemistry , analytical chemistry (journal) , crystallography , materials science , computational chemistry , crystal structure , thermodynamics , physics , optoelectronics , organic chemistry , acoustics , biochemistry , chromatography
Effects of surface‐adsorbed O and lattice O for the CeO 2 (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 CeO 2 (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 Ce 0.96 Mn 0.04 O 2 (111) and Ce 0.96 Fe 0.04 O 2 (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 CeO 2 (111) surface owing to the inertness of lattice O, which can be easily oxidized to HgO on Ce 0.96 Mn 0.04 O 2 (111) and Ce 0.96 Fe 0.04 O 2 (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 CeO 2 (111) catalysts. © 2019 Wiley Periodicals, Inc.