氧原子和羟基在Ni低指数表面的吸附动力学研究

应用5-参数Morse势方法模拟了O－Ni表面相互作用势，考察了氧原子在镍三个低指数表面的吸附特性.同时构造了羟基与Ni（100）、Ni（110）和Ni（111）表面相互作用的推广LEPS势，获得了羟基在表面的吸附位、吸附几何、结合能及本征振动等数据.理论结果表明，羟基垂直吸附于镍表面的高对称位是稳定的，垂直吸附于Ni（100）表面4-重洞位的吸附能为96.98 kJ•mol－1，垂直吸附于Ni（111）表面3-重洞位的吸附能为96.00 kJ•mol－1，在Ni（110）表面存在两种吸附态：垂直吸附于长桥位的吸附能为99.38 kJ•mol－1，倾斜14°吸附于赝势三重位吸附能为96.98 kJ•mol－1.理论结果与实验结果符合得较好.

Adsorption Dynamics of Oxygen Atom and Hydroxyl Radical on Low Index Nickel Surfaces

The interactional potential of O－Ni surface system was simulated by means of the 5-parameter.Morse potential,the adsorptive characteristics of an oxygen atom on low index nickel surface.An extended LEPS potential for the OH－Ni surface system was constructed.Data of adsorption sites,adsorption geometry,binding energy and eigenvibration etc.were obtained.These results show that high-symmetry sites are the most stable sites for OH perpendicular adsorption.Adsorption energies for OH perpendicular adsorption are 109.45 kJ•mol－1 at 4-fold hollow site on Ni (100),96.00 kJ•mol－1 at 3-fold hollow site on Ni (111).However,there are two adsorptive sites on Ni(110):one is the perpendicular adsorption at long-bridge site with adsorptive energy 99.38 kJ•mol－1 ;the other is a 14° inclined from the surface normal at phoney 3-fold site on Ni (110) with adsorptive energy 96.98 kJ•mol－1,the calculated results are in good agreement with the experimental ones.