CO分子和C、O和H原子在Ni_n(n=4～13)团簇表面吸附的密度泛函理论研究

DFT Study of Adsorption of Molecular CO, atomic C, O and H on Ni_n(n=4～13) Clusters

采用密度泛函理论（DFT）对Nin（n=4～13）团簇吸附CO分子和C、O和H原子进行了系统研究.结果表明：Nin（n=4～13）团簇对它们的吸附强度的大小顺序始终是C＞O＞H＞CO,择优吸附位点是谷位;吸附后,CO的键长与自由的C-O键长（1.140 （A））相比有所增加（0.016～0.071 （A））,这表明C-O键被削弱,CO被活化;比结合能（稳定性）由大到小的顺序是NinCO＞NinC＞NinO＞NinH和Nin,吸附后,团簇的稳定性普遍增加.

The adsorption of CO molecule and atomic C, O and H on Nin（n=4～13） clusters was simulated using density functional theory. The result indicated that the adsorption ability on Nin（n=4～13） clusters followed the order C〉O〉H〉CO at the most favorable sites （follow）; The elongate C-O bond and lower bond order of CO molecule supported that CO has been activated at different degrees; The average binding energy （stability） was in the sequence NinCO〉NinC〉NinO〉 NinH and Nin, and after adsorption, the stability of clusters generally increased.