硫醇分子在HMOR分子筛中吸附的量子化学研究

STUDY ON THIOL ADSORPTION IN H-MORDENITE BY QUANTUM CHEMISTRY

构造了包含1个完整十二元环的氢型丝光沸石(HMOR)的结构模型(12T),采用Dmol3程序中的密度泛函理论GGA/BLYP方法和DNP基组研究了硫醇分子在HMOR中的吸附,获得了吸附平衡构型和吸附能等信息。结果表明,硫醇分子主要通过其硫原子上的孤对电子与HMOR中质子酸位形成氢键而被吸附在其中;此外,硫醇分子中的氢原子与HMOR骨架氧之间还形成弱的氢键,对吸附复合物有一定的稳定作用。从吸附能数据看,在所研究的3种模型化合物中,甲硫醇分子与HMOR骨架的相互作用最强;在HMOR中,2种取向不同的正丙硫醇分子的吸附能明显不同。

A 12-membered rings cluster （12T） was constructed and used as the H-mordenite （HMOR） model. The adsorption of thiols in HMOR was investigated by using Dmol3 program and GGA/BLYP method and DNP basis set. The equilibrium configurations and adsorption energies of thiols adsorbed in 12TAl-H were obtained. The main interaction between thiols and HMOR took place through the action between the lone pair electrons of S and H＋ in HMOR. In addition, there were weak hydrogen bonds between the hydrogen atoms of thiols and the negatively charged oxygen atoms of HMOR framework, by which the adsorption complexes were further stabilized. The adsorption energy of CHaSH was the lowest, meaning that the action between CHaSH and HMOR framework was the strongest among the three thiols investigated. The adsorption energies of CHa（CH2）2SH with different location in HMOR were greatly different.