Inter-Doping ZrO₂-5.5RuO₂ Heterostructures for Enhanced Efficiency and Stability in Acidic Oxygen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Acid water electrolysis is key for sustainable hydrogen production.
• Ruthenium dioxide (RuO2) catalysts suffer from oxidative dissolution in acidic media, limiting their stability and activity.
• Developing robust catalysts is crucial to overcome the activity-stability dilemma.

Purpose of the Study:

• To engineer a highly active and stable oxygen evolution reaction (OER) catalyst for acidic conditions.
• To address the limitations of traditional RuO2 catalysts through interface engineering.
• To establish a new paradigm for green hydrogen production.

Main Methods:

• Fabrication of zirconium-ruthenium oxide heterostructures (ZrO2-xRuO2) using a metal-organic framework confined effect and fused salt mixing method.
• Characterization of the catalyst's structure, composition, and electrochemical performance.
• Evaluation of catalytic activity and long-term stability under acidic OER conditions.

Main Results:

• ZrO2-5.5RuO2 exhibited an ultralow overpotential of 137 mV at 10 mA cm-2, setting a new benchmark for acidic OER catalysts.
• The catalyst demonstrated a mass activity 32.3 times higher than commercial RuO2 at 250 mV overpotential.
• Exceptional long-term stability was achieved, with the catalyst operating for 655 hours, significantly outperforming commercial RuO2 (<6 hours).

Conclusions:

• The Zr-O-Ru interfacial junction in ZrO2-xRuO2 is responsible for enhanced activity and stability.
• Atomic-level interface engineering effectively optimizes the adsorption of reactive oxygen species and minimizes lattice oxygen involvement.
• This work presents a novel strategy for developing advanced electrocatalysts, paving the way for large-scale green hydrogen energy applications.