Atomic-level Ru-Ir mixing in rutile-type (RuIr)O₂ for efficient and durable oxygen evolution catalysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Proton exchange membrane water electrolysis (PEMWE) requires efficient and stable electrocatalysts for the oxygen evolution reaction (OER).
• Heteroatom-doped RuO2 shows promise by suppressing lattice oxygen involvement, preventing catalyst degradation.
• Challenges remain in selecting heteroatoms and achieving atomic-level integration with Ru.

Purpose of the Study:

• To develop a novel electrocatalyst by integrating OER-active Ir atoms into a RuO2 matrix.
• To enhance catalyst stability and activity by maximizing synergy between Ru and Ir centers.
• To steer the OER pathway away from lattice oxygen participation.

Main Methods:

• Integration of Ru and Ir atoms onto lattice parameter-modulated templates.
• Synthesis of (RuIr)O2/C electrocatalysts.
• Performance evaluation in PEMWE, including in situ spectroscopic analysis and computational calculations.

Main Results:

• The (RuIr)O2/C electrocatalysts achieved a current density of 4.96 A cm-2 and mass activity of 19.84 A mgRu+Ir-1 at 2.0 V.
• Synergistic effects between Ru and Ir dual-active sites were confirmed.
• Optimized binding energy with oxygen intermediates and stabilized Ru sites were observed, mitigating Ru dissolution.

Conclusions:

• The synergistic integration of Ir into RuO2 is a viable strategy for robust and active OER electrocatalysts in PEMWE.
• The developed (RuIr)O2/C material demonstrates significant potential for efficient water splitting applications.
• Understanding the interplay between Ru and Ir sites provides insights for designing next-generation electrocatalysts.