Dual-Function Zinc Modulation Stabilizes Ru Clusters on Spinel Oxide for Efficient and Durable Acid Water Oxidation

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing low-cost, high-performance ruthenium (Ru)-based anodes is critical for proton exchange membrane water electrolysis (PEMWE).
• Achieving both high activity and long-term stability in acidic oxygen evolution reaction (OER) remains a significant challenge.

Purpose of the Study:

• To synthesize and characterize a novel Ru cluster catalyst (Ru_clusters/ZnCo₂O₄) for enhanced PEMWE performance.
• To investigate the role of zinc (Zn) doping in stabilizing the catalyst structure and improving electronic properties for OER.

Main Methods:

• Synthesis of Ru clusters loaded on Zn-doped cobalt oxide spinel (ZnCo₂O₄).
• Electrochemical characterization including OER activity and durability testing in acidic media.
• Theoretical calculations and experimental validation to understand structure-property relationships.

Main Results:

• The Ru_clusters/ZnCo₂O₄ catalyst exhibited a low overpotential of 200 mV for OER.
• The catalyst demonstrated remarkable stability, operating for over 725 hours at 10 mA cm^-2 with a low decay rate.
• A PEMWE device using this anode operated stably for over 275 hours at 200 mA cm^-2.

Conclusions:

• Zinc doping transforms the support into a stable substrate, optimizing the electronic environment of Ru active sites for enhanced OER.
• The developed catalyst achieves a balance between high activity and durability, offering a new strategy for acidic OER catalyst development.
• This approach provides a paradigm for using inert metals to regulate support structures, leading to breakthroughs in catalyst activity and stability.