物理化学学报 >> 2011, Vol. 27 >> Issue (05): 1075-1080.doi: 10.3866/PKU.WHXB20110444

理论与计算化学 上一篇    下一篇

甲醇在FeS2(100)完整表面的吸附和分解

杜玉栋1, 赵伟娜1, 郭欣2, 章永凡1, 陈文凯1   

  1. 1. 福州大学化学系, 福州 350108;
    2. 华中科技大学煤燃烧国家重点实验室, 武汉 410074
  • 收稿日期:2010-12-15 修回日期:2011-03-06 发布日期:2011-04-28
  • 通讯作者: 陈文凯 E-mail:qc2008@fzu.edu.cn
  • 基金资助:

    国家自然科学基金(90922022), 华中科技大学煤燃烧国家重点实验室基金(FSKLCC0814)和福建省高等学校新世纪优秀人才计划(HX2006-103)资助项目

Adsorption and Dissociation of Methanol on Perfect FeS2(100) Surface

DU Yu-Dong1, ZHAO Wei-Na1, GUO Xin2, ZHANG Yong-Fan1, CHEN Wen-Kai1   

  1. 1. Department of Chemistry, Fuzhou University, Fuzhou 350108, P. R. China;
    2. State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 410074, P. R. China
  • Received:2010-12-15 Revised:2011-03-06 Published:2011-04-28
  • Contact: CHEN Wen-Kai E-mail:qc2008@fzu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (90922022), State Key Laboratory of Coal Combustion Foundation of Huazhong University of Science and Technology, China (FSKLCC0814), and New Century Excellent Talents Program in University of Fujian Province, China (HX2006-103).

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摘要：

采用基于第一性原理的密度泛函理论结合周期平板模型方法, 研究了甲醇分子在FeS2(100)完整表面的吸附与解离. 通过比较不同吸附位置的吸附能和构型参数发现: 表面Fe位为有利吸附位, 甲醇分子通过氧原子吸附在表面Fe位, 吸附后甲醇分子中的C―O键和O―H键都有伸长, 振动频率发生红移; 甲醇分子易于解离成甲氧基CH3O和H, 表面Fe位仍然是二者有利吸附位. 通过计算得出甲醇在FeS2(100)表面解离吸附的可能机理: 甲醇分子首先发生O―H键的断裂, 生成甲氧基中间体, 继而甲氧基C―H键断裂, 得到最后产物HCHO和H2.

关键词: 密度泛函理论, 甲醇, FeS2(100)表面, 吸附, 过渡态

Abstract:

First-principles calculations based on density functional theory (DFT) and the periodical slab model were used to study the adsorption and dissociation of methanol on the perfect FeS2(100) surface. The adsorption energy and the geometric parameters on the different adsorption sites showed that the Fe site was the most favorable adsorption site and O atoms were found to bind to Fe atoms. After adsorption, the C―O and O―H bonds of methanol were elongated and the vibrational stretch frequency was red shifted. The calculation results proved that methanol was prone to decomposition resulting in methoxy groups and hydrogen. We calculated the adsorption behavior of these methoxy groups and hydrogen on the FeS2(100) surface and found that the Fe sites were also the most favorable adsorption sites. A possible decomposition pathway was investigated using transition state searching methods: first the O―H bond of methanol was decomposed producing the intermediate methoxy group and subsequently the C―H bond of the methoxy group was broken resulting in final products of formaldehyde and hydrogen.

Key words: Density functional theory, Methanol, FeS2(100) surface, Adsorption, Transition state