Redox-Engineered Co─Cu─Zr Perovskites for Durable Anion Exchange Membrane Electrolysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is crucial for water electrolysis and energy storage but is limited by catalyst performance.
• Developing electrocatalysts with high activity and long-term stability is essential for efficient OER.

Purpose of the Study:

• To synthesize and characterize a novel mixed-metal perovskite, Ba(ZrₓCu<0xE1><0xB5><0xA7>Co₁₋ₓ₋<0xE1><0xB5><0xA7>)O₃₋<0xE2><0x82><0x91> (BZCC), for efficient OER in alkaline media.
• To investigate the catalytic mechanisms and structural properties of BZCC for enhanced OER performance.

Main Methods:

• Low-temperature hydrothermal synthesis of BZCC perovskite.
• Electrochemical characterization of BZCC for OER activity and durability.
• Application of BZCC in a single-cell anion exchange membrane water electrolyzer (AEMWE).

Main Results:

• BZCC exhibits dual activation of adsorbate evolution mechanism (AEM) and lattice oxygen oxidation mechanism (LOM) via Co redox flexibility.
• Cu incorporation enhances intrinsic activity, while Zr ensures structural stability against alkaline corrosion.
• BZCC shows a low overpotential of 238 mV at 10 mA cm⁻², with minimal degradation over 200 h.
• In an AEMWE, the BZCC anode achieved 1.0 A cm⁻² at 2.07 V and maintained stable operation for 25 h.

Conclusions:

• BZCC is a highly active and stable electrocatalyst for OER, driven by its unique combination of redox flexibility, electronic modulation, and structural integrity.
• The findings position BZCC as a promising candidate for scalable and sustainable anion exchange membrane water electrolyzers.