Heterophase RuO₂ oxygen evolution catalyst for durable proton exchange membrane water electrolysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ruthenium (Ru) dissolution is a major challenge for commercializing non-iridium (Ir) proton exchange membrane water electrolyzers (PEMWEs).
• Harsh anode operating conditions accelerate catalyst degradation, limiting device lifetime and efficiency.

Purpose of the Study:

• To develop a novel catalyst strategy that enhances the stability and activity of ruthenium-based catalysts for PEMWEs.
• To address the trade-off between activity and stability in oxygen evolution reaction (OER) catalysts.

Main Methods:

• Engineered a heterophase MoRuOx catalyst (AC-MoRuOx) with unique phase arrangements beyond conventional atomic ordering.
• Investigated catalyst performance in acidic oxygen evolution reactions (OER) and within proton exchange membrane water electrolyzer (PEMWE) devices.
• Analyzed the relationship between heterophase architecture, electronic structure, and catalyst stability.

Main Results:

• The AC-MoRuOx catalyst achieved 10 mA/cm² at a low 180 mV overpotential in OER, with stability exceeding 3000 hours.
• Demonstrated exceptional durability in PEMWEs: ≥2000 hours at 1.0 A/cm² and 1000 hours at 1.5 A/cm².
• Heterophase engineering optimized active-site density and structural integrity, resolving the activity-stability dilemma.

Conclusions:

• The heterophase MoRuOx catalyst design offers a promising solution for stable and efficient operation of non-iridium PEMWEs.
• This approach provides a new pathway for designing robust electrocatalysts by manipulating phase architecture and atomic arrangements.
• The developed catalyst significantly advances the commercialization prospects of PEMWE technology for green hydrogen production.