Direct Visualization of Catalytically Active Sites at the FeO-Pt(111) Interface

Area of Science:

• Surface science
• Heterogeneous catalysis
• Atomic-scale reaction dynamics

Background:

• Visualizing atomic-scale chemical reactions at interfaces is a significant challenge in surface science.
• Previous studies relied on indirect methods to understand catalytic activity at interfaces.

Purpose of the Study:

• To directly visualize the CO oxidation reaction at the FeO-Pt(111) interface at the atomic scale.
• To identify the specific sites responsible for catalytic activity in this inverse model catalyst.

Main Methods:

• In situ high-resolution scanning tunneling microscopy (STM) for time-lapsed imaging.
• Density functional theory (DFT+U) calculations to model reaction pathways.

Main Results:

• STM imaging directly identified catalytic activity at the FeO-Pt(111) interface.
• Fe-edges were confirmed as the most active sites for CO oxidation.
• DFT+U calculations indicated thermodynamically and kinetically favorable CO oxidation pathways on oxidized Fe-edges.

Conclusions:

• The FeO-Pt(111) interface, particularly Fe-edges, exhibits significant catalytic activity for CO oxidation.
• Direct atomic-scale visualization is achievable even at complex interfaces.
• This work provides fundamental insights into structure-activity relationships in heterogeneous catalysis.