物理化学学报 >> 2009, Vol. 25 >> Issue (03): 549-554.doi: 10.3866/PKU.WHXB20090325

研究论文 上一篇    下一篇

氢在沸石上的吸附行为

杜晓明 吴尔冬   

  1. 沈阳理工大学材料科学与工程学院, 沈阳 110168; 沈阳材料科学国家联合实验室, 中国科学院金属所, 沈阳 110016
  • 收稿日期:2008-10-21 修回日期:2008-12-16 发布日期:2009-03-02
  • 通讯作者: 杜晓明 E-mail:du511@163.com

Behavior of Adsorbed Hydrogen Molecules on Zeolites

 DU Xiao-Ming, WU Er-Dong   

  1. School of Materials Science and Engineering, Shenyang Ligong University, Shenyang 110168, P. R. China;  Shenyang National Laboratory for Materials Sciences, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
  • Received:2008-10-21 Revised:2008-12-16 Published:2009-03-02
  • Contact: DU Xiao-Ming E-mail:du511@163.com

摘要:

应用基于Ono-Kondo格子理论得到的通用吸附等温方程, 通过分析氢在不同温度下, 在沸石NaX、CaA、NaA和ZSM-5上的吸附数据, 确定了氢的最大单层吸附容量. 并引入维里吸附方程, 由第二维里吸附系数和圆柱孔的Lennard-Jones(12-6)势模型计算了氢与沸石微孔壁面的作用势. 结果表明, 通用吸附等温方程可较好地描述氢在沸石上的超临界吸附行为, 拟合所得的氢在沸石上的最大单层吸附容量与吸附剂相关, 而与吸附温度无关. 圆柱孔作用势模型计算所得的氢分子在沸石上的吸附作用势与吸附热相近. 氢分子间的作用力表现为吸引力.

关键词: 氢气, 沸石, 吸附容量, 吸附作用势

Abstract:

A general model for hydrogen adsorption was derived using Ono-Kondo lattice theory. The maximum monolayer adsorption capacities of hydrogen molecules on zeolites of NaX, CaA, NaA, and ZSM-5 were determined by fitting experimental adsorption data at different temperatures to the general model. The interaction potential between hydrogen molecules and pore surface atoms in the zeolite was calculated using gas-surface Virial coefficients and the Lennard-Jones (12-6) potential model for cylindrical pores. Results show that the general model can correctly describe supercritical experimental adsorption data of hydrogen on zeolites. Maximum monolayer adsorption capacities of hydrogen molecules on zeolites are dependent on the type of zeolite but independent of temperature. The adsorption interaction potential of the hydrogen-zeolite obtained from the above cylindrical pore model and gas-surface Virial coefficients agrees with a previously reported isosteric heat of hydrogen on zeolites. Our results indicate that the adsorption of hydrogen into zeolite pores is predominately caused by physisorption and a hydrogen-hydrogen attractive interaction.

Key words: Hydrogen, Zeolite, Adsorption capacity, Adsorption interaction potential

MSC2000: 

  • O647