Direct Visualization of Catalytically Active Sites at the FeO鈥揚t(111) Interface
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- 作者：Wilhelmine Kudernatsch ; Guowen Peng ; Helene Zeuthen ; Yunhai Bai ; Lindsay R. Merte ; Lutz Lammich ; Flemming Besenbacher ; Manos Mavrikakis ; Stefan Wendt
- 刊名：ACS Nano
- 出版年：2015
- 出版时间：August 25, 2015
- 年：2015
- 卷：9
- 期：8
- 页码：7804-7814
- 全文大小：1162K
- ISSN：1936-086X
文摘
Within the area of surface science, one of the 鈥渉oly grails鈥?is to directly visualize a chemical reaction at the atomic scale. Whereas this goal has been reached by high-resolution scanning tunneling microscopy (STM) in a number of cases for reactions occurring at flat surfaces, such a direct view is often inhibited for reaction occurring at steps and interfaces. Here we have studied the CO oxidation reaction at the interface between ultrathin FeO islands and a Pt(111) support by in situ STM and density functional theory (DFT) calculations. Time-lapsed STM imaging on this inverse model catalyst in O2 and CO environments revealed catalytic activity occurring at the FeO鈥揚t(111) interface and directly showed that the Fe-edges host the catalytically most active sites for the CO oxidation reaction. This is an important result since previous evidence for the catalytic activity of the FeO鈥揚t(111) interface is essentially based on averaging techniques in conjunction with DFT calculations. The presented STM results are in accord with DFT+U calculations, in which we compare possible CO oxidation pathways on oxidized Fe-edges and O-edges. We found that the CO oxidation reaction is more favorable on the oxidized Fe-edges, both thermodynamically and kinetically.