Catalytic activity for oxygen reduction reaction on platinum-based core-shell nanoparticles: all-electron density...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Proton exchange membrane fuel cells (PEMFCs) utilize platinum nanoparticles (NPs) as catalysts for oxygen reduction reactions (ORR).
• Platinum NPs often exhibit suboptimal catalytic activity due to strong binding of oxygen/hydroxyl species, leading to large overpotentials.
• Developing novel catalyst structures is crucial for overcoming these limitations and improving fuel cell efficiency.

Purpose of the Study:

• To theoretically investigate the catalytic activity of platinum-based core-shell nanoparticles (CSNPs) for ORR.
• To explore the influence of different 3d-5d transition metal cores on the performance of Pt CSNPs.
• To identify promising CSNP compositions for enhanced ORR catalysis.

Main Methods:

• Density functional theory (DFT) calculations were employed to examine the electronic and thermodynamic properties of CSNPs.
• The study systematically analyzed 12 different transition metal cores (groups 8-11) paired with a platinum shell.
• Comparison was made between CSNPs and bilayer catalysts to understand size effects.

Main Results:

• Pt CSNPs, particularly those with 3d transition metal cores, demonstrated enhanced catalytic activity for ORR.
• Trends in catalytic activity were correlated with the d-band center and electronic structure of the core metals.
• A significant size effect was observed, highlighting the potential for size-determined catalytic activity.

Conclusions:

• 3d transition metal-cored Pt CSNPs represent a promising strategy to improve ORR catalysis in fuel cells.
• The findings provide insights into optimizing catalyst design based on core material properties and nanoparticle size.
• This work facilitates the selection of efficient CSNP materials for advanced fuel cell applications.