物理化学学报 >> 2000, Vol. 16 >> Issue (11): 981 -986 .doi: 10.3866/PKU.WHXB20001105

研究论文 上一篇    下一篇

ITQ-1分子筛中二甲苯吸附特征的计算机模拟

朱丽荔, 侯廷军, 徐筱杰   

  1. 北京大学化学与分子工程学院 北京 100871
  • 收稿日期:2000-02-22 修回日期:2000-04-18 发布日期:2000-11-15
  • 通讯作者: 徐筱杰

Computer Simulation Studies of the Adsorption Behacisrs of Xylenes in ITQ-1 Zeolite

Zhu Li-Li, Hou Ting-Jun, Xu Xiao-Jie   

  1. College of Chemistry and Molecular Engineering,Peking Unicerstiy,Beijing 100871
  • Received:2000-02-22 Revised:2000-04-18 Published:2000-11-15
  • Contact: Xu Xiao-Jie

摘要:

用巨正则蒙特卡罗模拟研究了邻二甲苯和间二甲苯在ITQ-1分子筛中的吸附特征。模拟结果表明两种吸附质分子在分子筛骨架中的吸附特征不存在明显的差别。从两种吸附质分子在l2员环超笼之间运动的势能曲线,可以说明在通过l0员环窗口时,邻二甲苯和间二甲苯都需要克服较大的势垒,但邻二甲苯需要的激发能量明显大于间二甲苯,计算机模拟以及实验结果表明间二甲苯可以通过l0员环窗口到达分子筛的内部,而邻二甲苯则只能在分子筛的表面发生吸附或扩散。

关键词: ITQ-1, 巨正则蒙特卡罗模拟, 吸附, 扩散

Abstract:

The adsorption behaviors of xylenes in ITQ-l zeolite have been studied by using grand canonical Monte Carlo (GCMC) simulations.The simulated results indicate that the adsorption behavisrs of the studied sorbate molecules exhibit no obvious differences.Furthermore,the potential profile of xylenes migrating through the 10-MR windows interconnected cages have been determined,and the obtained results suggest that near 10-MR windows the potential barrier of o-xylene is significantly larger than that of m-xylene,which should block the diffusion of o-xylene into the interior of the zeolite,The theoretical calculations and experimental results show that m-xylene canmigrate through 10-MR windows systems interconnected 12-MR supercages and achieve the adsorption equilibria easily,while o-xylene can not overcome some potential barriers along 12-MR aupercages and arrive the iterior of the zeolite.

Key words: ITQ-1, Grand canonical Monte Carlo(GCMC), Adsorption, Diffusion