Ni(510)台阶面对氢分子解离吸附的影响

Effects of the Ni(510) Step Surface for the Dissociative Adsorption of Hydrogen Molecule

应用对势方法获得H_2／Ni（100）和H_2／Ni（510）相互作用体系的LEPS势能面，考察了氢分子在Ni（100）面上的解离吸附行为，理论计算结果和实验结果符合很好．对H_2／Ni（510）体系的研究表明，台阶的作用为：（1）在台阶下部，氢分子直接解离的最低能量反应途径赛区增大，且平动活化垒降低，（2）在台阶上部及台阶边棱处．前驱态的最低能量反应途径密度增大，因此台阶处成为氢分子解离和复合的活性部位．

The LEPS potential energy surfaces for the interaction of H2-Ni(100) and H2Ni(510) systems were obtained using the pairpotential method. The dissociative adsorption properties for H2 on Ni(100) surface were studied, theoretical results are in agreement with the expermental results.The role of the step in the dissociative adsorption properties for H2 on Ni(510) step surface is that (1) at the terraces u-nder the step, the direct dissociative paths are increased and the translational activation potential barriers axe decreased obviously, (2) at the terraces above the step and near step edge, the precursor dissociative paths are increased.Thus the active regions for the dissociation and association of H2 are situated near the step.