Surface-composition-driven patchy carbon shells unlock high activity and durability in PtCu oxygen reduction...

Area of Science:

• Catalysis
• Materials Science
• Nanotechnology

Background:

• Platinum-copper (PtCu) nanoparticles are crucial catalysts.
• Controlling nanoparticle structure is key to enhancing catalytic performance.
• Carbon incorporation and shell formation are strategies to improve catalyst stability and activity.

Purpose of the Study:

• To investigate the effect of sequential low-temperature CO and high-temperature Ar treatments on carbon-incorporated PtCu nanoparticles.
• To understand the mechanisms of Pt surface segregation and carbon shell formation.
• To evaluate the impact of these structural modifications on oxygen reduction reaction (ORR) activity and durability.

Main Methods:

• Synthesis of carbon-incorporated PtCu nanoparticles.
• Sequential treatment with carbon monoxide (CO) at low temperature and argon (Ar) at high temperature.
• Characterization of nanoparticle structure and surface composition (e.g., using electron microscopy, surface analysis techniques).
• Electrochemical evaluation of oxygen reduction reaction (ORR) performance and durability.

Main Results:

• Low-temperature CO treatment induced Pt surface segregation and localized carbon growth.
• High-temperature Ar treatment formed a patchy carbon shell.
• Selective near-surface copper (Cu) dealloying occurred.
• Treated nanoparticles exhibited boosted ORR activity.
• Enhanced durability and suppressed particle degradation were observed.

Conclusions:

• Sequential CO and Ar treatments effectively engineer PtCu nanoparticle structure for improved catalysis.
• The formed carbon shell protects the catalyst, while dealloying enhances intrinsic activity.
• This approach offers a promising strategy for developing durable and highly active electrocatalysts for the oxygen reduction reaction.