化学学报 ›› 2000, Vol. 58 ›› Issue (10): 1216-1220. 上一篇    下一篇

研究论文

MCM-22型分子筛中苯分子吸附行为的蒙特卡罗模 拟研究

侯廷军;朱丽荔;徐筱杰   

  1. 北京大学化学与分子工程学院
  • 发布日期:2000-10-15

Adsorption of benzene in MCM-22 zeolite by grand canonical monte carlo simulation

Hou Tingjun;Zhu Lili;Xu Xiaojie   

  • Published:2000-10-15

用巨正则统计系综蒙特卡罗模拟方法研究了纯硅MCM-22型分子筛(ITQ-1)中苯分子的吸附行为。结果表明苯分子在ITQ-1型分子筛中主要存在4个吸附位点。从苯分子粒子分布云图上可以看到苯分子的扩散和吸附主要在12元环超笼内发生。在苯分子的扩散过程中,S2位置附近的苯分子分布较为集中,而S3和S4附近的苯分子分布则较为离散。苯分子通过10元环窗口的运动路径势能面的计算结果表明,苯分子在12元环超笼内可以较为自由迁移,而通过10元环窗口从一个超笼扩散到附近的超笼时则需要较高的激发能量,这个能量大约为100kJ/mol。

关键词: 分子筛, 苯, 吸附, 蒙特卡罗模拟

The adsorption behaviors of benzene in ITQ-1 zeolite have been studied by using grand canonical Monte Carlo (GCMC) simulations. The results indicate that there exist four separate active adsorption sites of benzene in the ITQ-1 zeolite. Moreover, it can be found that the diffusion and migration of benzene mainly happed in 12-MR cavity. In the adsoption process, the benzene molecules near S2 site are generally localized, but the benzene molecules near S2 and S3 site are located in a relatively large area. The potential surface of benzene cross the 10-MR window indicates that in one 12-MR cavity, the benzene molecule can migrate from one place to another relatively freely, while relatively high activation energy (about 100kJ/mol) must be needed when it is to migrate from one 12-MR cavity to another 12-MR cavity nearby through the 10-MR windows.

Key words: MOLECULAR SIEVE, BENZENE, ADSORPTION, MONTECARLO SIMULATIONS

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