物理化学学报 >> 2011, Vol. 27 >> Issue (07): 1647-1653.doi: 10.3866/PKU.WHXB20110714

理论与计算化学 上一篇    下一篇

氢气在Na-MAZ和Li-MAZ沸石原子簇上的吸附

梁建明1, 章日光2, 赵强1, 董晋湘1, 王宝俊2, 李晋平1   

  1. 1. 太原理工大学精细化工研究所, 太原 030024;
    2. 太原理工大学煤科学与技术教育部和山西省重点实验室, 太原 030024
  • 收稿日期:2011-01-20 修回日期:2011-05-09 发布日期:2011-06-28
  • 通讯作者: 王宝俊, 李晋平 E-mail:wangbaojun@tyut.edu.cn; jpli211@hotmail.com
  • 基金资助:

    国家自然科学基金(20871090, 20976115, 20906066)资助项目

Hydrogen Adsorption on Zeolite Na-MAZ and Li-MAZ Clusters

LIANG Jian-Ming1, ZHANG Ri-Guang2, ZHAO Qiang1, DONG Jin-Xiang1, WANG Bao-Jun2, LI Jin-Ping1   

  1. 1. Research Institute of Special Chemicals, Taiyuan University of Technology, Taiyuan 030024, P. R. China;
    2. Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, P. R. China
  • Received:2011-01-20 Revised:2011-05-09 Published:2011-06-28
  • Contact: WANG Bao-Jun, LI Jin-Ping E-mail:wangbaojun@tyut.edu.cn; jpli211@hotmail.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20871090, 20976115, 20906066).

摘要:

采用基于密度泛函理论(DFT)的广义梯度近似(GGA)/PBE(Perdew-Burke-Ernzerhof)交换相关泛函和双数值基加p极化(DNP)基组对氢气分子在Na-MAZ和Li-MAZ沸石原子簇上的吸附进行了研究, 计算得到吸附复合物的平衡几何结构参数、振动频率以及吸附能等数据. 结果表明: MAZ沸石中存在四个稳定的吸附位点, 分别为SI′、SI″、SII′和SII″位点; 氢气分子在Na-MAZ沸石的SII″位点吸附时最稳定, 而在Li-MAZ沸石中, 氢气分子处于SI″和SII″位点时最稳定. 吸附能越大, 氢气分子键长越长, 振动频率减少也越多. Li-MAZ沸石对氢气的吸附能力要明显强于Na-MAZ沸石的吸附能力, 理论上Li-MAZ沸石具有更高的氢气储量, 可能是一种潜在的储氢材料.

关键词: MAZ沸石, 氢气, 吸附, 密度泛函理论, 广义梯度近似

Abstract:

Hydrogen adsorption on zeolite Na-MAZ and Li-MAZ clusters was investigated using density functional theory (DFT) with the generalized gradient approximation (GGA) of the Perdew-Burke- Ernzerhof (PBE) exchange-correction functional and the double numerical plus polarization (DNP) basis set. Equilibrium structural parameters, vibration frequencies, and adsorption energies were obtained and compared. The calculated results show that four stable adsorption sites are present on zeolite MAZ. They are designated SI′, SI″, SII′, and SII″, respectively. The most stable adsorption structure was hydrogen on the SII″ site of zeolite Na-MAZ and the hydrogen on the SI″ and SII″ sites of zeolite Li-MAZ were the most stable. We also found that larger adsorption energies indicate longer H―H bond distances and a lower vibration frequency shift. The adsorption ability of zeolite Li-MAZ toward hydrogen is stronger than that of zeolite Na-MAZ. Zeolite Li-MAZ has a higher theoretical hydrogen storage capacity and it may be a potential hydrogen storage material.

Key words: Zeolite MAZ, Hydrogen, Adsorption, Density functional theory, Generalized gradient approximation

MSC2000: 

  • O641