化工学报 ›› 2018, Vol. 69 ›› Issue (5): 1840-1845.DOI: 10.11949/j.issn.0438-1157.20171236

• 热力学 • 上一篇    下一篇

Fe3O4协同H2O2气相高级氧化单质汞的机理

周长松1,2, 杨宏旻1, 孙佳兴1, 祁东旭1, 毛琳1, 宋子健3, 孙路石3   

  1. 1. 南京师范大学能源与机械工程学院, 江苏 南京 210042;
    2. 南京师范大学化学与材料科学学院, 江苏 南京 210023;
    3. 华中科技大学煤燃烧国家重点实验室, 湖北 武汉 430074
  • 收稿日期:2017-09-11 修回日期:2018-01-02 出版日期:2018-05-05 发布日期:2018-05-05
  • 通讯作者: 周长松
  • 基金资助:

    国家自然科学基金项目(51676101,51376073);江苏省自然科学基金项目(BK20161558);中国博士后科学基金项目(2017M621779);江苏省高校自然科学基金项目(17KJB470009)。

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. 1. School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing 210042, Jiangsu, China;
    2. School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, Jiangsu, China;
    3. State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
  • Received:2017-09-11 Revised:2018-01-02 Online:2018-05-05 Published:2018-05-05
  • Supported by:

    supported by the National Natural Science Foundation of China (51676101, 51376073), the Natural Science Foundation of Jiangsu Province (BK20161558), the China Postdoctoral Science Foundation (2017M621779) and the College Natural Science Foundation of Jiangsu Province (17KJB470009).

摘要:

利用密度泛函理论分别研究了H2O2分子在Fe3O4(111)、(110)和(001)表面分解特性,并对单质汞在H2O2/Fe3O4体系的反应特性进行了研究。对比不同构型的结合能、Mulliken电荷转移和分态密度分析,详细讨论了H2O2分解产生羟基的规律以及Hg0的氧化态中间产物成键特性。结果表明:H2O2分子在Fe3O4(111)、(001) A和(110) A表面更容易分解产生羟基;不同表面产生的羟基对Hg0具有不同的氧化活性;Hg0在表面羟基的作用下可有效通过电荷转移实现氧化。对比分析了三种表面汞氧化态中间产物的脱附路径,HO—Hg—OH和Hg—OH的表面脱附是主要的反应路径。

关键词: 汞, 氧化, 密度泛函理论, 自由基, 表面

Abstract:

The decomposition properties of H2O2 molecule over Fe3O4 (111), (110), and (001) surfaces were systematically investigated by using density functional theory (DFT) calculations. Hg adsorption and oxidation mechanisms over H2O2/Fe3O4 system were studied. 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 was 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 activity of OH produced on different surfaces varies 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.

Key words: mercury, oxidation, density functional theory, radical, surface

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