胺类分子在LiMOR分子筛中吸附的量子化学研究  

Study on Amines Adsorption in Li-Mordenite by Quantum Chemistry

作　　者：蒋南[1] 袁淑萍[1] 秦张峰[1] 王建国[1] 焦海军[1] 李永旺[1] 

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001

出　　处：《催化学报》2004年第10期779-784,共6页

基　　金：国家自然科学基金资助项目 ( 2 0 0 73 0 5 7) .

摘　　要：采用量子化学方法 (ONIOM ,B3LYP/6 31G(d ,p) :HF/3 2 1G)研究了锂型丝光沸石 (LiMOR)的结构及其对胺类分子的吸附性能 .在校正基组迭加误差的基础上计算得到氨、甲胺、二甲胺和三甲胺分子的吸附热分别为 117 6 ,132 7,12 2 2和10 6 0kJ/mol,表明胺分子在LiMOR分子筛上吸附强度的次序为三甲胺 <氨 <二甲胺 <甲胺 .通过结构优化得到了吸附复合物的平衡几何参数、电子结构数据以及N H键伸缩振动频率 ,胺分子与分子筛之间的主要作用力为氮上的孤对电子和锂离子之间的静电作用力 。The two-layered ONIOM (B3LYP/6-31G(d,p):HF/3-21G) methods were employed to investigate the interaction of Li-mordenite (LiMOR) with several amines including ammonia, methylamine, dimethylamine and trimethylamine. The structure and electronic properties as well as the N-H bond stretching frequencies of the adsorption complexes showed that the main interaction between amines and LiMOR was taken place through the action between the lone electron pair of nitrogen and the Li + cation. In addition, there were weak hydrogen bonds between the hydrogen atoms of amines and the negatively charged oxygen atoms of the zeolite framework, which further stabilize the adsorption complexes. The calculated adsorption energy of NH 3, MeNH 2, Me 2NH and Me 3N on LiMOR was 117.6, 132.7, 122.2, and 106.0 kJ/mol, respectively, reflecting the different adsorption strength of these amines on LiMOR.

关 键 词：胺 吸附 锂 丝光沸石 ONIOM 量子化学 

分 类 号：O643[理学—物理化学]