物理化学学报 >> 2012, Vol. 28 >> Issue (09): 2051-2056.doi: 10.3866/PKU.WHXB201206281

理论与计算化学 上一篇    下一篇

镍镁铝类水滑石的超分子结构、电子性质及稳定性

倪哲明, 李远, 施炜, 薛继龙, 刘娇   

  1. 浙江工业大学化学工程与材料学院, 先进催化材料实验室, 杭州 310032
  • 收稿日期:2012-05-21 修回日期:2012-06-28 发布日期:2012-08-02
  • 通讯作者: 倪哲明 E-mail:jchx@zjut.edu.cn
  • 基金资助:

    浙江省自然科学基金(Y406069)资助项目

Supramolecular Structure, Electronic Property and Stability of Ni-Mg-Al Layered Double Hydroxides

NI Zhe-Ming, LI Yuan, SHI Wei, XUE Ji-Long, LIU Jiao   

  1. Laboratory of Advanced Catalytic Materials, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, P. R. China
  • Received:2012-05-21 Revised:2012-06-28 Published:2012-08-02
  • Contact: Ni Zhe-Ming E-mail:jchx@zjut.edu.cn
  • Supported by:

    The project was supported by the Natural Science Foundation of Zhejiang Province, China (Y406069).

摘要:

以Ni2+同晶取代Mg2+的方式构建镍镁铝类水滑石(HT)的周期性计算模型, 通过进行密度泛函理论计算,研究了含镍水滑石的的超分子结构、电子性质及稳定性. 结果表明, 随着镍离子逐渐取代镁离子, 金属离子之间的平均距离逐渐减小, 层间距逐渐增大, 与实验结果一致. 与此同时, 电子逐渐从主体层板向客体阴离子传递,导致主客体之间的静电作用力及整体超分子作用力逐渐增强, 结合能的绝对值逐渐增大, 体系的稳定性增加.在微观结构上, 电子传递行为使层板中平均金属―氧键键长逐渐减小, 且金属配位角的畸变情况得到一定程度的缓解, 这些变化都有利于形成更稳定的体系, 说明镍铝类水滑石在理论上比镁铝水滑石更稳定.

关键词: 镍镁铝类水滑石, 密度泛函理论, 微观结构, 电子性质, 稳定性

Abstract:

We established periodical structures for Ni-Mg-Al hydrotalcites (HT) by isomorphous substitution of Mg2+ with Ni2+. We discussed the supramolecular structure, electronic property, and stability of the systems according to computational results based on density functional theory. As Ni2+ content of increased, the average distance between metal cations decreased while the interlayer spacing gradually increased, in agreement with the experimental data. At the same time, electrons gradually transferred from layer to interlayer anions. As a result, the electrostatic interaction, whole supramolecular interaction, and absolute binding energy value of the system increased, improving system stability. Meanwhile, the average M-O bond length decreased, and the distorted O-M-O angles were weakened to some degree. All of these changes are beneficial to the formation of a stable system, so we conclude that Ni-Al-HT is more stable than Mg-Al-HT.

Key words: Ni-Mg-Al layered double hydroxide, Density functional theory, Microcosmic structure, Electronic property, Stability

MSC2000: 

  • O641