氧分子在Pt低指数面上的吸附和解离  

Adsorption and Dissociation of O_2 on Pt Low Index Surfaces

作　　者：董晨初[1] 王泽新[1] 刁兆玉[1] 

机构地区：[1]山东师范大学化学系

出　　处：《化学学报》2006年第6期489-495,共7页Acta Chimica Sinica

基　　金：山东省自然科学基金(No.Y2002B09)资助项目.

摘　　要：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860,930,1250cm-1进行了合理的指派.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 02 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 02 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.

关 键 词：5-MP 推广的LEPS势 吸附 解离 指纹性质 

分 类 号：O647.31[理学—物理化学]