中文摘要：

采用扫描隧道显微镜和X射线光电子能谱对含有次表层Fe的Pt表皮结构（Ptskin）,即0.4MLFe的Pt/Fe/Pt（111）表面,在1.1×10-7kPa氧气气氛退火过程中的变化进行了研究.结果表明,当退火温度为600K时,氧气在Pt/Fe/Pt（111）表面上解离吸附并诱导表面局域结构的重构;750K时次表层Fe可以扩散到表面并被氧化;当升至850K时,在样品表面形成单层FeO结构,并且FeO表面具有周期性的缺陷.这种缺陷是由于单层FeO薄膜的摩尔条纹单胞中fcc位上一个或多个氧原子缺失形成的,其中多原子空位被确定为缺失6个氧原子所致.FeO表面缺陷结构的研究为理解Fe-Pt催化剂在氧化气氛中的结构稳定性以及构造表面活性位提供一定的基础.

英文摘要：

The structural evolution of a Pt surface with 0.4 monolayer （ML） subsurface Fe on annealing in 1.1 × 10-7 kPa O2 was studied by scanning tunneling microscopy and X-ray photoelectron spectroscopy.When the annealing temperature was 600 K,only dissociative adsorption of O2 occurred,which induced the local restructuring of surface regions.At 750 K,subsurface Fe atoms segregated onto the surface and were oxidized.When the annealing temperature was increased to 850 K,well defined monolayer FeO islands with periodic arrays of defects were formed.The defects were located at the hexagonal closest packed sites （fcc） of FeO Moiré unit cells and were either single oxygen vacancies or multiple oxygen vacancies consisting of six missing O atoms.The formation of periodic defects on monolayer FeO islands may be a way to construct active sites on Pt-Fe model catalysts.