H2O在Pt(100)表面的预吸附态与高迁移性能

本文采用ASED-MO方法,计算了H₂O分子在Pt(100)面上不同吸附取向、不同吸附位置时的结合能,以及表面扩散激活能和扩散系数.计算结果表明,H₂0分子必须通过氢原子朝向衬底的预吸附态.才能进人氧原子朝向衬底的垂直顶位化学吸附状态.当H₂O分子处于上述预吸附态时,势能面极为平坦,扩散系数大,迁移性高. 关键词：

PRECURSOR STATES AND HIGH MOBILE PROPERTY OF H2O ON Pt(100) SURFACE

Using ASED-MO method, the binding energies for different adsorption orientations and positions of H₂O molecule on Pt(l00), and the activation energies and coefficient of surface diffusion are calculated. It is found that there are precursor states for H₂O chemisorption, through which the equilibrium geometry via O atom toward substrate on top position is reached. When H₂O molecule is in the precursor states, the potential surface is very flat, the diffusion coefficient is large and the mobility is high.