褐煤表面吸附水分子的微观机理

发布时间：2018-05-09 02:17

本文选题：褐煤表面 + 水分子　；参考：《动力工程学报》2016年04期

【摘要】：应用密度泛函理论在分子水平上研究了水在褐煤表面的微观吸附机理,在B3LYP/6-311G+(d,p)优化基础上,采用Gaussian09软件程序包计算得到褐煤表面构型及其不同煤水吸附构型,采用完全均衡校正法对其相互作用能校正重叠误差.运用Multiwfn程序和VMD软件,应用静电势分布图、散点图和约化密度梯度(RDG)填色等值图对不同褐煤表面模型进行图形化分析.结果表明:褐煤表面对水分子的吸附为物理吸附,属于弱相互作用,这些弱相互作用力以氢键作用为主,其余为范德华弱相互作用;羟基、羧基对水的吸附性最强,其他含氧基团(如醚键、甲氧基等)次之,苯环最弱;水分子吸附形成的相互作用区域并不简单地集中于某个基团或某个原子,而是与褐煤局部区域都形成一定的相互作用,这不仅增强了水分子的吸附作用,而且对褐煤结构产生较大影响.
[Abstract]:The microcosmic adsorption mechanism of water on lignite surface was studied by using density functional theory at molecular level. Based on the optimization of B3LYP/6-311G dapp, the surface configuration of lignite and its different coal-water adsorption configurations were calculated by Gaussian09 software package. The complete equalization correction method is used to correct the overlap error. By using Multiwfn program and VMD software, the surface models of different lignite were analyzed graphically by using electrostatic potential distribution, scatter plot and reduced density gradient (RDG) color equivalent map. The results show that the adsorption of water molecules on lignite surface is physical adsorption, which belongs to weak interaction, these weak interaction forces are mainly hydrogen bond, the others are van der Waals weak interaction, the adsorption of hydroxyl group and carboxyl group on water is the strongest. Other oxygen-containing groups (such as ether bonds, methoxyl groups, etc.) are second, and benzene rings are the weakest; the interaction regions formed by the adsorption of water molecules are not simply concentrated in a group or atom, but interact with the local regions of lignite to a certain extent. This not only enhances the adsorption of water molecules, but also has a great effect on the structure of lignite.
【作者单位】：华北电力大学能源动力与机械工程学院;广东粤电靖海发电有限公司;华北电力大学环境科学与工程学院;
【基金】：国家自然科学基金资助项目(51076045)
【分类号】：TD849.2;O641.1

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