Stabilizing Fe Single Atoms on Rutile-TiO₂(110) Surface Via Atomic Substitution

Area of Science:

• Materials Science
• Surface Chemistry
• Catalysis

Background:

• Efficient catalysis relies on stable anchoring of metal atoms on support surfaces.
• Understanding metal-support interactions at the atomic level is key to catalyst design.

Purpose of the Study:

• To identify and characterize different iron single-atom configurations on rutile-titanium dioxide (TiO2) (110) surfaces.
• To investigate the atomic-level mechanisms of metal-support interactions.

Main Methods:

• Utilized scanning tunneling microscopy (STM) for atomic-scale imaging.
• Employed density functional theory (DFT) calculations for theoretical analysis.

Main Results:

• Identified two primary Fe single-atom configurations: surface adsorption on oxygen sites (I) and substitution of surface titanium atoms (II).
• Demonstrated STM manipulation can induce transformation from configuration I to II.
• Observed formation of a dual Fe-Fe complex (configuration III) from a substitutional Fe atom.
• DFT revealed distinct electronic states (bandgap or conduction band) for each Fe species.

Conclusions:

• Provided atomistic insights into Fe single-atom configurations on TiO2.
• Highlighted the dynamic nature of Fe atoms on TiO2 surfaces.
• Laid the groundwork for understanding the performance of Fe single-atom catalysts supported on TiO2.