Revealing the atomic restructuring of Pt-Co nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Bimetallic nanoparticles are crucial in catalysis.
• Understanding their surface dynamics under reaction conditions is essential.

Purpose of the Study:

• To investigate the atomic restructuring of Platinum-Cobalt (Pt-Co) nanoparticles.
• To observe surface dynamics during oxidation and reduction cycles.

Main Methods:

• Aberration-corrected environmental transmission electron microscopy (ETEM).
• In-situ observation of Pt-Co nanoparticles in O2 and H2 atmospheres.

Main Results:

• Oxidation causes Cobalt (Co) migration to the surface, forming a strained Cobalt Oxide (CoO) film that evolves into islands.
• Atomic restructuring and film formation were captured over time.
• Reduction leads to Co migration back into the nanoparticle bulk, leaving a surface platinum (Pt) monolayer.

Conclusions:

• Pt-Co nanoparticles exhibit dynamic surface restructuring in response to atmospheric changes.
• The observed surface Pt monolayer after reduction has implications for catalytic applications.