化学学报 ›› 2000, Vol. 58 ›› Issue (8): 975-980. 上一篇    下一篇

研究论文

MgO缺陷和不规则表面吸附CO的能带和电子结构研究

李奕;李俊钱;吴立明;章永凡;周立新   

  1. 福州大学化学系.福州(350002);福州大学结构化学国家重点实验室
  • 发布日期:2000-08-15

The electronic structure of CO adsorption on MgO defective and irregular surfaces

Li Yi;Li Junqian;Wu Liming;Zhang Yongfan;Zhou Lixin   

  1. Fuzhou Univ, Dept Chem.Fuzhou(350002)
  • Published:2000-08-15

采用从头算程序优化MgO表面三种不同配位位置吸附CO构型,并用扩展休克尔紧束缚(EHT)晶体轨道方法对MgO的缺陷和不规则表面吸附CO的可能构型进行能带计算,讨论了能带结构及组成,不同构型吸附前后能带和成键性质的变化,以及吸附前后的电荷转移和吸附键的变化规律。研究结果发现,CO的C端更有利于在MgO固体表面的吸附,具有氧缺陷结构的MgO更有利于吸附分解CO。

关键词: 氧化镁, 吸附, 一氧化碳, 能带, 电子结构, 从头计算法

Using the geometric configuration optimized from ab initio calculation, the energy band structure of CO adsorption on MgO(001) defective and irregular surfaces were studied by EHT crystal orbital method. The structures and components of the bands have been discussed. By means of analyzing the changes of bonding, CO binds at Mg(3c) cations considerably stronger than at regular Mg(5c) and Mg(4c) sites. The charge redistributions in the CO molecule and the substrate are considered. It is shown that CO may bind to the surface with a slight preperence for the O-Mg^2^+-C(CO) interaction. The oxygen vacancy of MgO(001) surface is more beneficial to CO adsorption and decompose on the surface than other configurations.

Key words: MAGNESIUM OXIDE, ADSORPTION, CARBON MONOXIDE, BAND, ELECTRONIC STRUCTURE, AB INITIO CALCULATION

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