Interfacial oxygen under TiO2 supported Au clusters revealed by a genetic algorithm search.

Area of Science:

• Materials Science
• Surface Chemistry
• Catalysis

Background:

• Understanding metal-oxide interfaces is crucial for catalysis.
• Rutile titanium dioxide (TiO2) is a widely studied support material.
• Gold nanoparticles on TiO2 exhibit unique catalytic properties.

Purpose of the Study:

• Investigate the oxidation of one-dimensional (1D) periodic gold rods on rutile TiO2(110).
• Determine the adsorption sites and electronic interactions of oxygen at the interface.
• Explore the potential for CO oxidation catalysis at the gold/TiO2 interface.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Simulated oxidation of gold rods on the TiO2(110) surface.
• Analyzed adsorption energies and charge transfer.

Main Results:

• Evidence of interface oxidation between gold and TiO2.
• Oxygen atoms adsorb on Ti atoms beneath the gold rod.
• Stabilization of adsorbed oxygen via charge transfer from gold.
• No low-energy pathways for CO oxidation were identified.
• Weak adsorption of CO on cationic gold sites at the interface perimeter.

Conclusions:

• The gold/TiO2 interface undergoes oxidation, influencing reactivity.
• The observed interface structure does not favor CO oxidation under the studied conditions.
• Weak CO adsorption limits catalytic activity at the interface perimeter.