Mechanism of Hg removal by gaseous advanced oxidation process with Fe3O4 and H2O2

ZHOU Changsong1,2 YANG Hongmin1 SUN Jiaxing1 QI Dongxu1 MAO Lin1 SONG Zijian3 SUN Lushi3

(1.School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu, China 210042)
(2.School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, China 210023)
(3.State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, Hubei, China 430074)

【Abstract】The decomposition properties of H2O2 molecule over Fe3O4 (111), (110), and (001) surfaces were systematically investigated by using density functional theory (DFT) calculations. The Hg adsorption and oxidation mechanisms over H2O2/Fe3O4 system were studied. The binding energies, optimized geometries, Mulliken population, and molecular orbital analysis of partial density of states (PDOS) between Hg and H2O2/Fe3O4 surfaces were proposed. The most favored configurations of H2O2 decomposition, which were associated with the generation mechanism of OH groups, as well as the intermediates of Hg species were discussed. The results showed that OH radicals were more likely produced on Fe3O4 (111), (001) A, and (110) A surfaces. The oxidative activityies of OH produced on different surfaces varied a lot. In addition, Mulliken charge population revealed Hg0 oxidation when the systems were in equilibrium because a large number of electrons transferred from Hg0 to the surface hydroxyl. The calculated binding energies suggested that the process of HO–Hg–OH and Hg–OH generation were exothermic on Fe3O4 surface with H2O2. The desorption analysis showed that HO–Hg–OH and Hg–OH intermediates had a lower desorption energy when they detached from the surface.

【Keywords】 mercury; oxidation; density functional theory; radical; surface;

【DOI】

【Funds】 National Natural Science Foundation of China (51676101, 51376073) Natural Science Foundation of Jiangsu Province (BK20161558) China Postdoctoral Science Foundation (2017M621779) College Natural Science Foundation of Jiangsu Province (17KJB470009)

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This Article

ISSN:0438-1157

CN: 11-1946/TQ

Vol 69, No. 05, Pages 1840-1845

May 2018

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Article Outline

Abstract

  • Introduction
  • 1 Calculation method and model
  • 2 Results and discussion
  • 3 Conclusion
  • References