化学学报 ›› 2008, Vol. 66 ›› Issue (2): 170-174. 上一篇    下一篇

研究论文

钇二氢化反应热力学函数的研究

于桂凤*,1,蒋刚2,徐国亮3,潘维1,朱正和2   

  1. (1青岛农业大学理学院 青岛 266109)
    (2四川大学原子与分子物理研究所 成都 610065)
    (3河南师范大学物理与信息工程学院 新乡 453007)
  • 投稿日期:2007-05-21 修回日期:2007-07-18 发布日期:2008-01-28
  • 通讯作者: 于桂凤

Study of the Thermodynamic Function of Yttrium Reacted with H2

YU Gui-Feng*,1 JIANG Gang2 XU Guo-Liang3 PAN Wei1 ZHU Zheng-He2   

  1. (1 Department of Science, Qingdao Agricultural University, Qingdao 266109)
    (2 Institute of Atomic and Molecular Physics, Sichuan University, Chendu 610065)
    (3 College of Physics and Information Engineering, Henan Normal University, Xinxiang 453007)
  • Received:2007-05-21 Revised:2007-07-18 Published:2008-01-28
  • Contact: YU Gui-Feng

用密度泛函方法B3LYP/SDD/6-311++G**计算了YH2的微观性质. 并用分子总能量中的振动能Ev代替固态能量0705212, 振动熵SEv代替固态熵的近似方法, 以及考虑到电子能量的变化, 计算了固态YH2(D, T)的焓H和熵S, 得到不同温度下Y与H2, D2, T2反应的ΔH, ΔS, ΔG及氢化反应平衡压力, 导出了与温度的依赖关系. 计算结果表明, YH2(s)的生成热为199.25 kJ•mol-1, 与实验值210.00及 225.94 kJ•mol-1非常接近, 说明近似方法的正确性.

关键词: YH2, 分子结构, 热力学函数

Density functional (B3LYP/SDD/6-311++G**) method with relativistic effective core potential (RECP) has been used to compute the microcosmic characters of YH2, and to calculate energy E, thermodynamic functions of YH2(D, T). Considering the characteristics of different motion types, the vibration energy and vibration entropies of the molecules were assumed to be the corresponding values of their solid states. ΔH, ΔS, ΔG and hydrogen isotope equilibrium pressures of the hydrogenation reaction at different temperatures have been calculated based on this approximation. The enthalpy of formation of YH2(s) at 298 K is 199.25 kJ•mol-1 , Which is close to the experimental value 210.00 and 225.94 kJ•mol-1. The results show that the present method is feasible to theoretical study on hydrogen storage materials.

Key words: YH2, molecular structure, thermodynamic function