受限于MER型沸石中水的分子动力学模拟  

Molecular dynamics simulation of water molecular confined in MER type zeolite

作　　者：石勤 戴浩 黄雪莉 

机构地区：[1]NN大学化学化工学院,新疆煤炭洁净转化与化工过程重点实验室,新疆乌鲁木齐830046

出　　处：《计算机与应用化学》2016年第9期983-988,共6页Computers and Applied Chemistry

基　　金：国家自然科学基金资助项目(21166022)

摘　　要：针对受限于MER型沸石中水的结构性质和扩散性质进行分子动力学模拟,为MER型沸石的制备及离子交换提供了理论依据。结果表明:H_(2)O在不同阳离子的MER型沸石中具有不同的结构性质。K^+与H_(2)O形成的水合阳离子在MER型沸石合成中起到了模板剂的作用。随着温度的升高,MER型沸石中H_(2)O的有序度下降,沸石骨架外阳离子的水合能力下降;H_(2)O在MER型沸石中的非键势能逐渐增大,H_(2)O的扩散系数均相应增大。H_(2)O在不同阳离子的MER型沸石中的扩散活化能大小顺序为:K-MER型沸石>Na-MER型沸石>NH_4-MER型沸石。MER型沸石骨架及骨架外的阳离子对H_(2)O的扩散性质有较大的影响。The structure character and diffusion behavior of water confined in MER type zeolite were investigated using molecular dynamics simulation method. The study is of importance theoretical foundation for preparation and cations exchange of MER type zeolite. The simulation results show that the structure character of water confined is of difference in the different kinds of cation MER type zeolite. The hydrogen-bonded network of potassium and water forms a structure-directing agent that acts as an inorganic template in the formation of MER type zeolite. With the increasing of temperature, the degree of order of water confined and hydration strength of non-framework cations in MER type zeolite decrease, meanwhile, non-bond energy of simulation system and diffusion coefficient of water confined in MER type zeolite increase. The order of diffusion activation energy of water confined in the different kinds of cation MER type zeolite is K-MER type zeolite 〉 Na-MER type zeolite 〉 NHa-MER type zeolite. Zeolite framework and extra-framework cations have great influence on diffusion behavior of water confined in MER type zeolite.

关 键 词：水 MER型沸石 扩散 分子动力学模拟 

分 类 号：TQ177.11[化学工程—硅酸盐工业]