Ordered PdCu-Based Nanoparticles as Bifunctional Oxygen-Reduction and Ethanol-Oxidation Electrocatalysts

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Commercialization of fuel cells requires advanced electrocatalysts for oxygen reduction reaction (ORR) and liquid fuel oxidation.
• Current platinum-based catalysts face limitations in activity and stability, presenting a significant challenge.

Purpose of the Study:

• To develop superior non-platinum electrocatalysts with enhanced activity and stability for ORR and ethanol-oxidation reaction (EOR).
• To investigate the effect of composition and intermetallic phase ordering on nanoparticle performance.

Main Methods:

• A colloidal chemistry technique was employed to synthesize structurally ordered palladium-copper-based nanoparticles (NPs).
• Composition was controlled, ranging from PdCu to PdCuNi and PtCuCo alloys.
• Density functional theory (DFT) calculations were used to understand the catalytic mechanisms.

Main Results:

• Ordered PdCuCo NPs demonstrated significantly improved activity and stability for ORR and EOR compared to disordered PdCuM NPs and commercial catalysts (Pt/C, Pd/C).
• The enhanced performance is attributed to catalytically active hollow sites, ligand effects, and compressive strain on the Pd surface.

Conclusions:

• Structurally ordered PdCuCo NPs represent a promising alternative to platinum-based electrocatalysts for fuel cell applications.
• Tuning nanoparticle composition and intermetallic phase is crucial for optimizing electrocatalytic performance.