Y_n(n=2-8)团簇吸附CO_2的密度泛函理论研究

Density function theory study of the adsorption of CO_2 on Y_n(n =2-8) clusters

运用密度泛函理论,研究了CO_2在Y_n(n=2-8)团簇表面的吸附结构和电子性质.结果表明:CO2吸附于Y_n(n=2-8)团簇表面时,线型的分子结构畸变为三角形构型.Y_nCO_2表现出了较大的吸附能(大于3eV).吸附使体系的能隙表现出了奇偶振荡效应.吸附后,C-O键伸长,C原子由电子施体变为受体,O原子所带电子数也显著增加.在所有尺寸中,Y_4CO_2、Y_6CO_2稳定性最好.

A density function theory calculation was performed to study the structures and electronic properties of YnCO2 （n=2-8） clusters. The results show that the linear structure of free CO2 molecule is distorted as the triangle structure. The YnCO2 （n=2-8） species exhibit large adsorption energies （above 3eV）, as well as the even-odd oscillation effects of the energy gap.The C-O bond length becomes longer after adsorption. The C atoms accept more electrons compared to the donor of the free CO2 molecules, and the amounts of the accepted electrons of O atoms increase clearly. Both Y4CO2 and Y6CO2 exhibit relatively higher stability.