Jiang Yixuan, Zhu Yaguang, Zhou Dechun, Jiang Zhao, Si Nan, Stacchiola Dario, Niu Tianchao
Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, No. 200, Xiaolingwei 210094, China.
Center for Functional Nanomaterials, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973-5000, USA.
J Chem Phys. 2020 Feb 21;152(7):074710. doi: 10.1063/1.5136279.
Monolayer iron oxides grown on metal substrates have widely been used as model systems in heterogeneous catalysis. By means of ambient-pressure scanning tunneling microscopy (AP-STM), we studied the in situ oxidation and reduction of FeO(111) grown on Au(111) by oxygen (O) and carbon monoxide (CO), respectively. Oxygen dislocation lines present on FeO islands are highly active for O dissociation. X-ray photoelectron spectroscopy measurements distinctly reveal the reversible oxidation and reduction of FeO islands after sequential exposure to O and CO. Our AP-STM results show that excess O atoms can be further incorporated on dislocation lines and react with CO, whereas the CO is not strong enough to reduce the FeO supported on Au(111) that is essential to retain the activity of oxygen dislocation lines.
生长在金属衬底上的单层氧化铁已被广泛用作多相催化的模型体系。借助常压扫描隧道显微镜（AP-STM），我们分别研究了在金（111）上生长的FeO(111)被氧气（O）和一氧化碳（CO）原位氧化和还原的过程。FeO岛表面存在的氧位错线对O解离具有高活性。X射线光电子能谱测量清楚地揭示了在依次暴露于O和CO后FeO岛的可逆氧化和还原过程。我们的AP-STM结果表明，过量的O原子可以进一步结合在位错线上并与CO反应，而CO的还原能力不足以还原负载在金（111）上的FeO，而这对于保持氧位错线的活性至关重要。
