CO在δ-Pu(111)面吸附行为的周期性密度泛函理论研究  

A periodical density functional theory study of CO adsorption on δ-Pu(111) surface

作　　者：熊晓玲[1] 魏洪源[1] 罗顺忠[1] 刘国平[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《分子科学学报》2009年第1期50-54,共5页Journal of Molecular Science

基　　金：中国工程物理研究院科学技术发展基金资助项目(2007A02001);中国工程物理研究院科学技术发展基金资助项目(2007B02004)

摘　　要：利用量子化学中的密度泛函理论结合周期模型方法研究了CO分子在δ-Pu(111)面的吸附行为.通过对不同吸附位置的吸附能和平衡几何结构比较发现,CO分子在δ-Pu(111)面的吸附C端吸附比O端吸附更有利,属于较强的化学作用,最稳定的吸附方式为心式垂直吸附,桥式次之,顶式最不稳定.心式垂直吸附的吸附能为-1.236eV,C原子吸附位距离Pu表面0.2122nm,C—O键长0.1208nm.CO与Pu配位数目是决定化学吸附的主要因素,配位的Pu原子数目越多,化学成键越稳定.Mulliken电荷分析表明CO和Pu表面的作用主要发生在第一层,另外两层几乎没有影响.CO adsorption on δ-Pu（lll） surfaces using the generalized gradient approximation of the density functional theory with PW91 functionals has been studied. For the δ-Pu（ 111 ） surface, the O-down adsorption is less stable than the C-down adsorption which is found to be a strong chemisorption.The center position of δ-Pu（111） surface is the preferred adsorption site with chemisorption energy of - 1.236 eV and distance of 0.212 2 nm and C--O bond length of 0. 120 8 nm. The coordination numbers play a significant role in the chemical bonding process. Mulliken charge distribution analysis indicates that the interaction of Pu with CO mainly takes place in the first layer and that the other two layers are only slightly affected. The adsorption of CO adsorptiom on 8-Pu surfaces make the surface work functions of Pu metal distinctly increased.

关 键 词：CO分子 δ-Pu(111)面 表面吸附 

分 类 号：O641[理学—物理化学]