高等学校化学学报 ›› 2024, Vol. 45 ›› Issue (4): 20230497.doi: 10.7503/cjcu20230497

• 物理化学 • 上一篇    下一篇

Cl2和O2在TiC(100)表面共吸附行为的密度泛函理论分析

陈荣1, 温良英1(), 岳东1, 杨仲卿2   

  1. 1.重庆大学材料科学与工程学院
    2.能源与动力工程学院, 重庆 400044
  • 收稿日期:2023-12-06 出版日期:2024-04-10 发布日期:2024-03-04
  • 通讯作者: 温良英 E-mail:cquwen@cqu.edu.cn
  • 基金资助:
    国家自然科学基金(51974046)

Density Functional Theory Analysis of Coadsorption Behavior of Cl2 and O2 on TiC(100) Surface

CHEN Rong1, WEN Liangying1(), YUE Dong1, YANG Zhongqing2   

  1. 1.School of Materials Science and Engineering
    2.School of Energy and Power Engineering,Chongqing University,Chongqing 400044,China
  • Received:2023-12-06 Online:2024-04-10 Published:2024-03-04
  • Contact: WEN Liangying E-mail:cquwen@cqu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(51974046)

摘要:

基于密度泛函理论的第一性原理从头计算方法, 建立了Cl2和O2在TiC(100)表面的共吸附模型. 通过分析吸附能、 电荷密度和偏态密度(PDOS)等参数, 研究了Cl2和O2在TiC(100)表面的反应机理, 发现解离后的Cl原子和O原子与TiC(100)表面的原子均成键, 从而破坏了Ti—C键. Cl2分子在吸附过程中充当电子的受体, 得到与之成键的Ti原子贡献的电子, O2分子在吸附过程中也充当电子的受体, 得到C原子贡献的电子. TiC(100)表面在吸附分子后, Ti—C成键轨道上电子占据数变少, 反键轨道上电子占据数增多, Ti原子与C原子之间的成键作用减弱. 同时, Ti3d与Cl3s, Cl3p发生轨道重叠杂化作用, O2p轨道和C2p轨道存在较强的共振峰, Cl原子和O原子与TiC表面相互作用强烈.

关键词: 碳化钛, 吸附行为, 氯气, 氧气, 密度泛函理论

Abstract:

Based on the first-principles ab initio calculation method of density functional theory(DFT), the coadsorption model of Cl2 and O2 molecules on the TiC(100) intact surface was established. The reaction mechanism of Cl2 and O2 molecules on the TiC(100) intact surface was studied by analyzing adsorption energy, charge density, partial density of states(PDOS) and other parameters. And it was found that the dissociated Cl and O atoms bond with the TiC(100) surface atoms, thus breaking the Ti—C bond. The Cl2 molecule acts as an electron acceptor during the adsorption process, obtaining electrons contributed by the Ti atom that bonds with it, and the O2 molecule also acts as an electron acceptor during the adsorption process, obtaining electrons contributed by the C atom. On the surface of TiC(100), the number of electrons occupied in the bonding orbitals of Ti—C decreases, and the number of electrons occupied in the antibonding orbitals increases, which indicates the bonding between Ti and C atoms is weakened. At the same time, Ti3d has orbital overlapping hybridization with Cl3s and Cl3p, and there are strong formant peaks in O2p and C2p orbits, and Cl and O atoms interact strongly with TiC surfaces.

Key words: Titanium carbide, Adsorption behavior, Chlorine gas, Oxygen, Density functional theory

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