H_2O和O_2在Al(111)表面吸附的密度泛函理论研究  

Density functional study of H_2O and O_2 adsorption on Al(111)surface

作　　者：雷小丽[1] 杨丽霞[1] 刘明星[1] 张玉新[1] 冯军 

机构地区：[1]中国地质大学材料科学与化学工程学院,湖北武汉430074 [2]三一集团精益质量总部工艺装备研究院涂装所,湖南长沙410110

出　　处：《计算机与应用化学》2011年第6期793-796,共4页Computers and Applied Chemistry

基　　金：国家科技基础条件平台建设项目(2005DKA10400-CT-1-08-06)

摘　　要：采用第一原理密度泛函理论中的广义梯度近似计算方法对H_2O和O_2分子在Al(111)表面的吸附性质进行了结构、能量和电子分析,系统研究了这2种气体分子在Al(111)表面的吸附行为及其与Al(111)表面的相互作用机理。计算结果表明:H_2O分子易在Al(111)表面的top位吸附且构型倾斜时最稳定,整个吸附过程为弱的化学吸附;吸附过程中表面铝原子的电子向H_2O分子发生转移,H_2O分子自身的构型仅受微扰作用。O_2分子在Al(111)表面的吸附倾向于以分子键平行于表面,表面铝原子向O_2分子的电荷转移是O_2分子解离的驱动力,吸附过程中O_2分子易发生解离,解离后的氧原子稳定吸附于fcc位,其次为hcp位,整个吸附过程为强的化学吸附。The adsorption behaviors of H2O2 and O2 molecule on Al（111）surface were investigated systematically by first-principle calculation based on density functional theory（DFT）with generalized gradient approximation（GGA）and the interaction mechanisms between these molecules and Al （111）surface were explored initially.The calculation results about the geometry,energy and electronic behaviors showed that the H2O2 molecule was apt to be adsorbed at the top site by weak chemisorption with the molecular axis titled away from the surface normal.Partial charge transferred from Al（111）surface to the H2O2 molecule during the adsorption,and there was little variation about the configuration of H2O2 molecule adsorbed,which was only affected by the perturbation.It was found that O2 molecule was preferred to be adsorbed on Al（111）surface with its molecular bond parallel to the Al（111）surface.The dissociation of the O2 molecule was mainly driven by the charge transfer from Al（111）surface to the O2 molecule.Once O2 molecule approached the Al（111）surface,the dissociation of O2 molecule occurred spontaneously.The O atoms dissociated were inclined to be adsorbed at fcc and hcp sites on Al（111）surface by strong chemisorption,and the fcc site was found to be more preferred.

关 键 词：密度泛函理论 Al(111)表面 吸附 H2O分子 O2分子 

分 类 号：TG171[金属学及工艺—金属表面处理] O647.31[金属学及工艺—金属学]