The decisive role of Au in CO diffusion on Pt surfaces: a DFT study

Area of Science:

• Materials Science
• Surface Chemistry
• Catalysis

Background:

• Metallic surface modification with a second metal is key for electrocatalyst development.
• Understanding the influence of specific adatoms on surface reactivity is crucial.

Purpose of the Study:

• To investigate the role of gold (Au) adatoms on platinum (Pt) surfaces.
• To determine the effect of Au on carbon monoxide (CO) adsorption and diffusion on Pt.
• To provide insights into designing advanced electrocatalysts.

Main Methods:

• First-principles calculations using density functional theory (DFT).
• Analysis of various adsorption sites on single-crystal Pt structures (open and staggered configurations).
• Application of climbing image nudged elastic band (CI-NEB) and potential energy surfaces (PES) for diffusion studies.

Main Results:

• Gold adatoms significantly alter the adsorption and diffusion behavior of CO on Pt surfaces.
• The presence of Au was found to inhibit the movement of CO towards highly reactive Pt sites.
• Distinct trends in CO diffusional behavior were identified based on adsorption site and configuration.

Conclusions:

• Gold adatoms on platinum surfaces act as barriers, controlling CO mobility.
• This finding enhances the understanding of bimetallic surface effects in electrocatalysis.
• The study provides a foundation for the rational design of more effective polycrystalline electrocatalysts.