化学学报 ›› 2006, Vol. 64 ›› Issue (6): 489-495. 上一篇    下一篇

研究论文

氧分子在Pt低指数面上的吸附和解离

董晨初,王泽新*,刁兆玉   

  1. (1山东师范大学化学系 济南 250014)
    (2滨州学院化学与化工系 滨州 256600)
  • 投稿日期:2005-06-30 修回日期:2005-11-20 发布日期:2006-03-28
  • 通讯作者: 王泽新

Adsorption and Dissociation of O2 on Pt Low Index Surfaces

DONG Chen-Chu, WANG Ze-Xin*, DIAO Zhao-Yu   

  1. (1 Department of Chemistry, Shandong Normal University, Jinan 250014)
    (2 Department of Chemistry and Chemical Engineering, Binzhou University, Binzhou 256600)
  • Received:2005-06-30 Revised:2005-11-20 Published:2006-03-28
  • Contact: WANG Ze-Xin

应用原子和表面簇合物相互作用的5参数Morse势方法(简称5-MP)构造推广的LEPS势对O2-Pt分子体系进行了系统的研究, 获得了O2分子在Pt的2个低指数面(111)和(110)重构面上的吸附几何、结合能和振动频率等临界点性质; 计算结果显示O2在Pt(111)面上难解离, 且存在超氧化吸附态, 同时, 应用表面分子解离限和晶面解离距的概念分析了(111)面上的解离机理; 并根据分子指纹性质, 将O2在Pt(110)缺行重构面上出现的振动频率860, 930, 1250 cm-1进行了合理的指派.

关键词: 5-MP, 推广的LEPS势, 吸附, 解离, 指纹性质

The extended London-Enyring-Polanyi-Sato (LEPS) of O2-Pt single crystal plane systems was constructed by means of the 5-parameter Morse potential (5-MP). Both adsorption and dissociation of O2 on Pt low index surfaces mainly including (111) and (110) reconstruction surfaces were investigated with extended LEPS in detail. All critical characteristics of the system obtained, such as adsorption geometry, binding energy, eigenvalues for vibration, etc., were in good agreement with the experimental results. Our calculated results suggested that the dissociation of O2 on Pt(111) surface should be difficult and superoxo-like state would exist likely. Meanwhile, the concepts of the molecular dissociation limit and the surface dissociation distance were used to analyze the dissociation mechanism of O2 on Pt(111) surface. Moreover, the vibration frequencies of 860, 930 and 1250 cm-1 produced by O2 adsorbed on Pt(110) reconstruction surface were assigned logically on the basis of the properties of the molecular fingerprint.

Key words: 5-parameter Morse potential, extended London-Enyring-Polanyi-Sato, adsorption, dissociation, fingerprint property