甲烷在Ir(111)面上吸附的密度泛函理论研究
The adsorption of the methane on the metal Ir(111) surface at a coverage of 0.25ML in a (2×2) unit cell has been investigated using a first-principles based density functional approach employing a plane-wave basis set and periodic boundary condition with generalized gradient approximation(GGA-PW91).The quantum chemical calculation were conducted using the Cambridge Serial Total Energy Package(CASTEP),which was used to obtain optimized structures and energies.In all calculation,the methane and the top four layers of the metal atom were allowed to relax.For calculated results of 12 adsorption configurations of four adsorption sites (the top site,the bridge site,the hcp hollow site and the fcc hollow site)described by one H atom,two H atoms and three H atoms respectively point toward the metal surface in every adsorption site,we found that the adsorption energy of the methane and Ir(111) surface is very weak ranging from 39mev to 46mev.All optimized structures,the adsorption energy of every adsorption site are bigger when two H atoms point toward the metal surface.We have calculated the electronic density of state (DOS) and projection density of state (PDOS) of the adsorbed species.Ni d-band with the methane molecule is a chemical interaction in the optimized configurations.
Methane Iridium Density functional calculations Density of state
马浚
中国工程物理研究院核物理与化学研究所,四川绵阳,621900
国际会议
南京
英文
644-652
2012-05-13（万方平台首次上网日期，不代表论文的发表时间）