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采用密度泛函理论与周期平板模型相结合的方法,对物种C_2H_x(x=4～6)在Ni(111)表面的top,fcc,hcp和bridge位的吸附模型进行了结构优化、能量计算,得到了各物种较有利的吸附位;并对最佳吸附位进行密立根电荷和总态密度分析.结果表明:C_2H_6和C_2H_4在Ni(111)表面的最稳定吸附位都是top位,吸附能分别是-36.41和-48.62 kJ·mol~(-1),物种与金属表面吸附较弱;而C_2H_5在Ni(111)表面的最稳定吸附位hcp的吸附能是-100.21 kJ·mol~(-1),物种与金属表面较强;三物种与金属表面之间都有电荷转移,属于化学吸附.
The density functional theory and the periodic plate model were used to optimize the adsorption model of species C_2H_x (x = 4 ~ 6) on the top, fcc, hcp and bridge of Ni (111) The more favorable adsorption sites for each species were obtained, and the most suitable adsorption sites were analyzed for the molar ratio of root-tip to total-state density.The results showed that the most stable adsorption sites of C_2H_6 and C_2H_4 on Ni (111) (-36.41 and -48.62 kJ · mol -1), respectively. The adsorption of H_2 on the surface of Ni (111) was -100.21 kJ · mol ~ (-1) 1) Species and metal surface is strong; the charge transfer between the three species and the metal surface belongs to chemical adsorption.