团簇Au_(n+1)^(-1)、Au_(n)Cr^(-1)(n=1-10)吸附CO的密度泛函理论研究  

Density functional study of interaction of CO with anion Cr-doped gold clusters and anion gold clusters

作　　者：王必利 宋蕊 仝亮 WANG Bi-Li;SONG Rui;TONG Liang(Department of Basic,Institute of PLA Army Engineering University,Nanjing 211101,China)

机构地区：[1]陆军工程大学基础部,南京211101

出　　处：《原子与分子物理学报》2021年第6期77-85,共9页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11304394);江苏省自然科学基金(BK20171397);陆军工程大学基础学科科研基金(KYJBJQZL1917);陆军工程大学励志基金(JBLZJJ1911)。

摘　　要：采用密度泛函理论对CO在阴离子团簇Au_(n+1)^(-1)、 Au_(n)Cr^(-1)(n=1-10))表面的吸附做了系统研究.结果表明,团簇Au_(n+1)CO^(-1)、 Au_(n)CrCO^(-1)的基态结构是在团簇Au_(n+1)^(-1)、Au_(n)Cr^(-1)最低能量结构的基础上吸附CO形成;吸附后的CO键长变长,振动频率减小,表明CO分子被活化;取值相同时,Au_(n)CrCO^(-1)的平均结合能高,表明团簇Au_(n+1)CO^(-1)掺杂Cr后稳定性升高. HOMO-LOMO能隙结果表明Au_(n+1)CO^(-1)替代掺杂Cr原子后团簇的化学活性得到了提升,Au_(n)CrCO^(-1)、 Au_(n+1)CO^(-1)团簇能隙具有奇偶振荡的现象;轨道电荷分析表明CO与团簇相互作用实质是C原子与成键Au原子或Cr原子间转移电荷,CO在与团簇相互作用过程中O原子轨道电荷分布几乎没有发生变化.The adsorptions of CO on the surfaces of anion Cr-doped gold clusters and anion gold clusters have been systematically investigated by density functional theory. The results indicate that the stable structures of Au_(n)CrCO^(-1)andAu_(n+1)CO^(-1)(n=1-10) are generated by CO being adsorbed on the lowest energy structures of Au_(n)Cr^(-1) and Au_(n+1)^(-1). The increased CO bond length and the reduced CO vibration frequence demonstrate the activation of the CO molecule. The higher average binding energy of Au_(n)CrCO^(-1) indicates that the stability of Au_(n+1)CO^(-1) is increased by Cr-doping. The energy gaps of Au_(n)CrCO^(-1) and Au_(n+1)CO^(-1) clusters exhibit an odd-even oscillatory behavior, and the result show that the chemical activity of Au_(n+1)CO^(-1) is improved by Cr-doping. The orbital charge layout indicates that the interaction between CO and Au_(n)Cr^(-1), Au_(n+1)^(-1) is essentially contributed by the transfer of charges between C atom and Au atom or Cr atom bonded to C atom, while charge distribution of O atom hardly changes during the interactions between CO and Au_(n)Cr^(-1), Au_(n+1)^(-1) clusters.

关 键 词：金团簇 基态构型 能隙 轨道电荷分布 

分 类 号：O641[理学—物理化学]