几种常用离子液体阴离子吸附SO_2行为的DFT计算  

Density Functional Theory Study on the SO_2 Adsorption on Several Ionic Liquid Anions

作　　者：邢旭伟[1] 姚淑娟[1] 周成冈[1] 古桂芬[1] 吴金平[1] 

机构地区：[1]中国地质大学理论化学与计算材料学研究所,湖北武汉430074

出　　处：《武汉大学学报（理学版）》2008年第2期162-166,共5页Journal of Wuhan University:Natural Science Edition

基　　金：中国地质大学青年基金资助项目(CUGQNL0519)

摘　　要：采用第一原理密度泛函理论(DFT)计算方法研究了常用的几种离子液体阴离子(Tf2N-,BF4-,PF6-)对二氧化硫(SO2)的吸附行为,计算了这几种阴离子吸附SO2分子的几何结构、吸附能以及SO2的振动频率.研究发现,3种离子液体阴离子与SO2分子之间的相互作用力介于物理吸附和化学吸附作用之间,三者对SO2分子吸附能力的强弱顺序依次为:BF4-,Tf2N-,PF6-.多个SO2分子在这些阴离子上的吸附也表现出相同的吸附强弱顺序.结果表明,SO2在离子液体中的溶解度会随着SO2和阴离子之间的相互作用强弱而变化.A first-principle density functional functional study is reported on the SO2 adsorption behav- ior on several ionic liquid anions （Tf2N- , BF4- and PF6 ）. By detailed analyzing the structural features, vibrational frequencies and energetics of the anion-SO2 systems, it is found that the anion-SO2 interaction ranges between physisorption and weak chemisorption with a relative adsorption strength sequence of BF4 ）Tf2N-）PF6-. Further calculations of multiple SO2 molecules adsorption on these anions also give the same interaction intensity sequence. Compared with the available experimental reports, the calculations suggest that the solubility of SO2 in ionic liquids should qualitatively vary with respect to the anion-SO2 interaction.

关 键 词：离子液体 阴离子 二氧化硫 密度泛函理论 

分 类 号：O648[理学—物理化学]