Interactions between oxygen atoms on Pt(100): implications for ordering during chemisorption and catalysis

Area of Science:

• Surface Science
• Computational Chemistry
• Materials Science

Background:

• Understanding chemisorbed oxygen interactions on metal surfaces is vital for catalysis.
• Oxygen ordering influences reactivity and surface phenomena on platinum group metals.
• The (1x1)-Pt(100) surface is a model system for studying adsorption processes.

Purpose of the Study:

• To investigate the interactions between chemisorbed oxygen atoms on the (1x1)-Pt(100) surface using DFT.
• To elucidate the factors governing oxygen ordering and striped phase formation.
• To provide insights into coadsorption and reaction mechanisms involving oxygen and CO.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Analysis focused on oxygen adsorption sites and inter-atomic interactions on Pt(100).
• Calculations determined interaction energies for different oxygen site configurations.

Main Results:

• Oxygen atoms preferentially adsorb at bridge sites on the (1x1)-Pt(100) surface.
• A significant difference in interaction strength was observed between oxygen pairs at different bridge sites.
• Strong repulsion exists between oxygen pairs separated by a platinum atom, while weak interaction occurs for pairs separated by a fourfold hollow site.

Conclusions:

• The DFT findings explain the prevalence of striped (nx1)-O ordering.
• These interactions are critical for understanding oxygen ordering in both single-species adsorption and coadsorption systems.
• The study provides a fundamental understanding of surface ordering relevant to heterogeneous catalysis.