Atomic-Level CuO_x-CoO_x-Pd Interfacial Engineering Enables Hierarchical Synergy for High-Efficiency ORR Pathways and...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Sluggish oxygen reduction reaction (ORR) kinetics and high platinum catalyst cost hinder alkaline fuel cell (AFC) technology.
• Developing efficient, low-cost ORR catalysts is crucial for advancing AFCs.

Purpose of the Study:

• To engineer a novel catalyst with enhanced ORR activity and stability for AFCs.
• To elucidate the synergistic catalytic mechanism at the heterointerface.

Main Methods:

• Synthesis of Cu-decorated CoO@Pd catalyst.
• Structural and spectroscopic analyses (e.g., PFY-XANES/EXAFS).
• Electrochemical testing in AFCs.

Main Results:

• Atomic CuOₓ species reconstruct the Pd-Co-Cu interface, creating oxygen vacancies (O_V).
• A multi-site cooperative pathway involving O_Vs and Pd enhances ORR kinetics.
• The catalyst achieved a high onset potential (0.935 V) and mass activity (1.6 × 10⁴ mA mg_Cu^-1), outperforming Pt/C by two orders of magnitude.
• AFC devices with the catalyst showed a 60% higher peak power density than Pt/C.

Conclusions:

• Atomic CuOₓ interface engineering is a viable strategy for high-performance, noble-metal-efficient ORR catalysts.
• The catalyst's performance is attributed to a synergistic multi-site mechanism.
• This work paves the way for cost-effective and efficient alkaline fuel cell technologies.