物理化学学报 >> 2010, Vol. 26 >> Issue (02): 415-421.doi: 10.3866/PKU.WHXB20100217

量子化学及计算化学 上一篇    下一篇

AlCl歧化反应分解法制备金属铝过程中[AlCl]n的形成机理

陈秀敏, 杨斌, 陶东平, 戴永年   

  1. 昆明理工大学真空冶金国家工程实验室, 昆明 650093; 昆明理工大学材料与冶金工程学院, 昆明 650093
  • 收稿日期:2009-07-06 修回日期:2009-11-03 发布日期:2010-01-26
  • 通讯作者: 陈秀敏 E-mail:chenxiumin9@sina.com

Formation Mechanism of [AlCl]n during Production of Aluminum by AlCl Disproportionation

CHEN Xiu-Min, YANG Bin, TAO Dong-Ping, DAI Yong-Nian   

  1. National Engineering Laboratory of Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, P. R .China; Faculty of Materials and Metallurgy Engineering, Kunming University of Science and Technology, Kunming 650093, P. R .China
  • Received:2009-07-06 Revised:2009-11-03 Published:2010-01-26
  • Contact: CHEN Xiu-Min E-mail:chenxiumin9@sina.com

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摘要：

利用密度泛函理论(DFT)中的广义梯度近似(GGA)法, 对氧化铝真空还原氯化歧化法制备金属铝的过程中[AlCl]n(n=1-10)团簇的稳定结构、能量和团簇形成过程的过渡态及其振动频率进行了理论研究, 预测了其基态结构及成长趋势. 结果表明: [AlCl]n(n=1-10)团簇可能存在的结构都是以[Al]n骨架外接n个Cl原子成型, 且具有较好的几何对称性; 从过渡态计算得到的活化能来看, 正过程的活化能总是比逆过程的活化能要小, 即[AlCl]n(n=1-10)团簇具有较好的成长趋势. 以上研究结果有助于进一步了解用碳热还原氯化歧化法制备金属铝过程中液态金属铝的生成.

关键词: 密度泛函理论, [AlCl]n团簇, 铝, 歧化反应, 过渡态

Abstract:

Density functional theory with the generalized gradient approximation was used to determine the geometries, energies, transition states, and vibrational frequencies of the [AlCl]n(n=1-10) clusters that form during the production of aluminum by the carbothermic reduction-disproportionation reaction. The ground state and trends observed during the formation of [AlCl]n were confirmed. Results indicate that the ground state geometric configurations of the [AlCl]n(n=1-10) clusters are frameworks of [Al]n bound to n Cl atoms and they have excellent geometric symmetry. Activation energies obtained from transition state calculations indicate that the activation energy of the reverse process is always higher than that of the forward process. This means that AlCl tends to form [AlCl]n. Our results can help in the understanding of this aluminumproduction mechanismduring the carbothermic reduction-disproportionation reaction.

Key words: Density functional theory, [AlCl]n clusters, Aluminum, Disproportionation, Transition state