Multi-Step Screening-Guided Core-Shell RuO₂@TaO_x Nanorods Electrocatalyst for Acidic Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Acidic oxygen evolution reaction (OER) is crucial for green hydrogen production.
• Ruthenium dioxide (RuO2) is active but unstable in acidic media.
• Need for stable electrocatalysts for acidic OER.

Purpose of the Study:

• To screen high-melting-point metal oxides as protective layers for RuO2.
• To investigate the role of protective layers in acidic OER.
• To develop a stable and active RuO2-based catalyst for acidic OER.

Main Methods:

• Computational screening of metal oxides.
• Synthesis of RuO2@TaOx core-shell catalyst.
• Electrochemical testing (overpotential measurements).
• Operando quick X-ray absorption spectroscopy (Quick-XAS).

Main Results:

• Ta-related oxide identified as the optimal protective layer.
• RuO2@TaOx exhibited low overpotentials (163 mV at 10 mA cm-2, 232 mV at 100 mA cm-2).
• TaOx layer prevented RuO2 dissolution and improved charge transfer.
• Operando Quick-XAS confirmed Ru as active site and TaOx preventing over-oxidation.

Conclusions:

• TaOx serves as an effective protective layer for RuO2 in acidic OER.
• The RuO2@TaOx core-shell structure significantly enhances OER activity and durability.
• Computational screening is a viable strategy for designing advanced catalysts.