羟烷基胺功能化离子液体吸收SO_2的量子化学计算(英文)  

Quantum Chemical Calculation of Hydroxyalkyl Ammonium Functionalized Ionic Liquids for Absorbing SO_2

作　　者：李学良[1] 陈洁洁[1] 罗梅[1] 陈祥迎[1] 李培佩[1] 

机构地区：[1]合肥工业大学化学工程学院,可控化学与材料化工安徽省重点实验室,合肥230009

出　　处：《物理化学学报》2010年第5期1364-1372,共9页Acta Physico-Chimica Sinica

基　　金：supported by the Annual Key Scientific Research Foundations of Anhui Province,China(08020203005,07020203003);Major Scientific and Technological Project of Anhui Province,China(08010202124)~~

摘　　要：采用量子化学中的密度泛函理论(DFT)对羟烷基胺离子液体(HyAAILs)与二氧化硫(SO2)的相互作用进行了研究.通过几何结构优化,电荷分布和热力学参数计算等来确定离子液体中能够有效吸收SO2的官能团.HyAAILs与SO2反应形成平均距离为0.240nm的S—N键,导致电荷从ILs转移到SO2以及S—O键长和O—S—O键角的改变.气态和液态模型的计算结果表明,标准吉布斯函数变(△G苓)主要取决于阳离子的结构和分子质量.阳离子结构影响了吸收反应能垒,对于三种阳离子体系的反应活化能顺序为:Ea(secondary)<Ea(tertiary)<Ea(primary).理论计算结果得到了实验数据的验证,羟乙基伯胺离子液体吸收的SO2理论摩尔分数与文献中的实验数据非常接近.本研究提供了一种预测和验证功能离子液体性质的有效方法.Interactions between hydroxyalkyl ammonium ionic liquids（HyAA ILs） and sulfur dioxide（SO2） were investigated by quantum chemical calculations using first-principles density functional theory.The optimized geometry,charge distribution,and thermodynamic parameters were obtained and used to identify the effective groups in the ILs that absorb SO2.HyAA ILs react with SO2 and form S—N bonds with an average distance of 0.240 nm.This reaction results in charge transfer from ILs to SO2 as well as changes in the S—O bond length and the O—S—O bond angle.The calculated results from the gas and liquid state models indicate that the standard Gibbs free energy change（△G ） of the absorption reaction is mainly determined by the geometry of these cations and their molecular weight.The cation structure influences the energy barrier of the absorption reaction and the activation energy（Ea） changes as follows：Ea（secondary）Ea（tertiary）Ea（primary）.The theoretical results were evaluated against experimental data and the molar fraction values of SO2 for the primary ammonium IL-SO2 system are in good agreement with the experimental results.This work provides an effective method for predicting and verifying the properties of functionalized ILs.

关 键 词：密度泛函理论 羟烷基胺离子液体 热力学性质 活化能 实验验证 

分 类 号：O641.121[理学—物理化学]