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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (11): 1043-1049. 上一篇    下一篇

研究论文

丙三醇脱水反应机理的密度泛函理论研究

黄金保1，刘朝*,1,2，魏顺安3，黄晓露1,2   

  1. (1重庆大学动力工程学院 重庆 400030)
    (2重庆大学低品位能源利用技术及系统教育部重点实验室 重庆 400030)
    (3重庆大学化学化工学院 重庆 400030)
  • 投稿日期:2009-09-02 修回日期:2009-12-16 发布日期:2010-01-19
  • 通讯作者: 黄金保 E-mail:huangjinbao76@126.com
  • 基金资助:

    国家自然科学基金

Density Functional Theory Study on the Dehydration Mechanism of Glycerine

Huang Jinbao1 Liu Chao*,1,2 Wei Shunan3 Huang Xiaolu1,2   

  1. (1 College of Power Engineering, Chongqing University, Chongqing 400030)
    (2 Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education, ChongqingUniversity, Chongqing 400030)
    (3 College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030)
  • Received:2009-09-02 Revised:2009-12-16 Published:2010-01-19

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被引次数

22 | 6

为了理解纤维素热解初期的脱水反应机理, 采用Gaussian 03程序中的密度泛函理论UB3LYP/6-31＋＋G(d,p) 方法, 对模型化合物丙三醇脱水反应机理进行了量子化学理论研究. 设计了6种可能的脱水反应途径, 对各种反应的反应物、产物和过渡态的结构进行了能量梯度全优化, 计算了不同温度下各反应途径的标准热力学和动力学参数. 计算结果表明: 除了形成中间体IMa和IMb的反应外, 其它反应均为吸热反应; 温度高于400 K时, 丙三醇开始发生脱水反应; 与1-2-脱水反应相比, 1-3-脱水反应的反应势垒更低, 其活化能为233.75 kJ/mol; 当反应加入金属离子Li＋时, 有利于脱水反应的发生, 这时1-2-脱水反应的活化能为201.95 kJ/mol, 1-3-脱水反应的活化能为202.14 kJ/mol.

关键词: 丙三醇, 脱水反应, 密度泛函理论(DFT)

For understanding the dehydration mechanism in initial pyrolysis of cellulose, dehydration reaction mechanism of the glycerine as a model was investigated using UB3LYP/6-31＋＋G(d,p) methods in Gaussian 03 package. Six kinds of paths of dehydration reaction were designed, and the equilibrium geometries of the reactants, transition states and products were optimized, and the standard thermodynamic and kinetic parameters of every reaction path in different temperature ranges were calculated. The calculation results show that every reaction except the reactions of formation of the intermediates IMa and IMb is endothermic processes and dehydration reaction of the glycerine can take place when temperature of reaction exceeds 400 K. Compared to 1-2-dehydration reaction, 1-3-dehydration reaction is liable to take place, in which activation energy is about 233.75 kJ/mol. Addition of metal ions Li＋ would be in favor of dehydration of the glycerine, and activation energy for 1-2-dehydration of the glycerine with addition of metal ions Li＋ is about 201.95 kJ/mol, and that for 1-3-dehydration is about 202.14 kJ/mol.

Key words: glycerine, dehydration reaction, density functional theory