高等学校化学学报

高等学校化学学报 ›› 2010, Vol. 31 ›› Issue (12): 2438.

• 研究论文 • 上一篇    下一篇

铜锌铝三元水滑石畸变结构和稳定性的理论研究

倪哲明,姚萍,刘晓明,王巧巧,胥倩   

  1. 浙江工业大学化学工程与材料科学学院, 先进催化材料实验室, 杭州 310032
  • 收稿日期:2010-05-14 修回日期:2010-09-06 出版日期:2010-12-10 发布日期:2010-12-06
  • 通讯作者: 倪哲明 E-mail:jchx@zjut.edu.cn
  • 作者简介:倪哲明, 女, 博士, 教授, 主要从事无机功能材料的研究.
  • 基金资助:

    浙江省自然科学基金(批准号: Y406069)资助.

Theory Study on the Distorted Structure and Stability of Copper\|Zinc\|Aluminum Layered Double Hydroxides

NI Zhe-Ming*, YAO Ping, LIU Xiao-ing, WANG Qiao-iao, XU Qian   

  1. Laboratory of Advanced Catalytic Materials, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, China
  • Received:2010-05-14 Revised:2010-09-06 Online:2010-12-10 Published:2010-12-06
  • Contact: NI Zhe-Ming E-mail:jchx@zjut.edu.cn
  • About author:倪哲明, 女, 博士, 教授, 主要从事无机功能材料的研究.
  • Supported by:

    the Natural Science Foundation of Zhejiang Province

PDF (PC)

被引次数

26

摘要： 通过构建水滑石(CuxZn3-xAl-LDHs)周期性计算模型，基于密度泛函理论，用CASTEP程序模块，进行模型的几何全优化，对各体系的结构参数，氢键，Mulliken电荷布居，结合能等进行分析，探究体系中的Jahn–Teller效应和结构稳定性。计算结果表明，层板中Cu2+与Zn2+交错排列的构型比较稳定。随着层板上Cu2+取代Zn2+的增多，晶胞对称性变差，但铜的Jahn–Teller效应对中心三价铝离子的影响较小。CuxZn3-xAl-LDHs (x=0-3)体系中离子键基本上逐渐变强，共价键逐渐变弱，体系整体上由共价型晶体向离子型晶体转变。体系中Jahn–Teller效应导致的畸变会使主客体作用力增强，其中静电作用力减弱，氢键强度变大，且氢键作用更占优势。总体上，体系的结合能绝对值逐渐减小，体系稳定性降低，这对于合成含铜的LDHs材料具有理论指导意义。

关键词: 水滑石, 畸变角, Jahn–Teller效应, 结合能, 密度泛函理论

Abstract: We proposed a periodic interaction model for the layered double hydroxides, CuxZn3-xAl-LDHs. Based on density functional theory, the geometry of CuxZn3-xAl-LDHs was optimized using the CASTEP program. Jahn–Teller effect and the stability was investigated by analyzing the geometric parameters, hydrogen-bonding, charge populations, and binding energies. Results showed that the structure of staggered arrangement of Cu2+ and Zn2 + in the layer was relatively stable. As the amount of Cu2+ substituted Zn2 + in the layer increased, the symmetry of unit cell became weaker, and Jahn–Teller effect of the copper had little effect on the central Al3 +. The strength of electrovalent bond became stronger while the strength of covalent bond became weaker with the increase of Cu2+ substituted Zn2 + in the layer, so the covalent crystal of CuxZn3-xAl-LDHs transited to the ionic crystal gradually. The distortion caused by Jahn–Teller effect made an enhanced supermolecular interaction between the host layer and the guest, the strength of electrostatic interactions became weaker while the strength of hydrogen-bonding became stronger, and hydrogen-bonding was superior to the electrostatic interaction. In general, the absolute value of he binding energy decreased gradually with an increase in the number of Cu2+, then the chemical stability of the system got worse, and it was significant for synthesis of Cu-LDHs.

Key words: Layered double hydroxides, Distortion angle, Jahn–Teller effect, Binding energy, Density functional theory

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