低覆盖度CO分子在 Ni(110)面的吸附研究

Study on adsorption of CO molecules on Ni (110) surface with low coverage

利用密度泛函理论研究了低覆盖度下CO分子在Ni(110)表面的吸附结构和电子态.研究结果表明:在低覆盖度情况下, CO分子优先垂直吸附在短桥位,其次是顶位和长桥位.垂直短桥位吸附、顶位吸附相应的振动频率分别是1850.52 cm-1、1998.08cm-1.态密度的研究结果表明:CO分子和Ni原子在-10 eV-8 eV,-8 eV—-6 eV及1 eV-5 eV能量范围内发生了杂化作用.-10ev-8ev能量范围内的杂化主要来源于C、O原子的s轨道、pz轨道与Ni原子s、p、d轨道的杂化作用.-8ev—-6ev能量范围内的杂化作用主要来源于C、O原子的py、 px轨道与Ni原子d、s轨道的杂化作用.轨道间的杂化作用是吸附作用的主要来源.我们计算的吸附位置与相应的振动频率与相关实验结果基本一致.

The adsorption structure and electron state of CO on Ni(110) surface with low coverage were studied by density functional theory. The results showed that under the condition of low coverage, CO molecules are preferentially adsorbed in short bridge position, followed by the top position, and then in long bridge position. The corresponding vibration frequencies of vertical short bridge adsorption and top adsorption are 1850.52 cm-1 and 1998.08 cm-1, respectively. The results of state density show that CO molecule and Ni atom are hybridized in the energy ranges of-10 eV-8 eV,-8 eV--6 eV and 1 eV-5 eV. The hybridization in the energy range of-10 eV-8 eV mainly comes from the hybridization between the s and pz orbitals of C and O atoms and the s, p and d orbitals of Ni atoms. The hybridization in the energy range of-8 eV--6 eV mainly comes from the hybridization of the py and px orbitals of atoms C and O and the d and s orbitals of atoms Ni. Hybridization between orbitals is the main source of adsorption.The adsorption position and corresponding vibration frequency we calculated are basically consistent with relative experimental results.