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 (O2) and carbon monoxide (CO), respectively. Oxygen dislocation lines present on FeO islands are highly active for O2 dissociation. X-ray photoelectron spectroscopy measurements distinctly reveal the reversible oxidation and reduction of FeO islands after sequential exposure to O2 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.

中文翻译：

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在室温下可逆氧化和还原金负载的氧化铁岛。

在金属基质上生长的单层氧化铁已广泛用作非均相催化中的模型系统。通过环境压力扫描隧道显微镜（AP-STM），我们分别研究了氧气（O2）和一氧化碳（CO）在Au（111）上生长的FeO（111）的原位氧化和还原。FeO岛上存在的氧位错线对O2的离解非常活跃。X射线光电子能谱测量清楚地揭示了在连续暴露于O2和CO后，FeO岛的可逆氧化和还原。我们的AP-STM结果表明，过量的O原子可以进一步掺入位错线并与CO反应，而CO为强度不足以还原负载在Au（111）上的FeO，这对于保持氧错位线的活性至关重要。