Iron-Induced Localized Oxide Path Mechanism Enables Efficient and Stable Water Oxidation

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Sluggish oxygen evolution reaction (OER) kinetics and poor performance of non-noble metal electrocatalysts hinder anion exchange membrane water electrolyzer (AEMWE) development.
• Developing efficient and stable electrocatalysts is crucial for advancing AEMWE technology.

Purpose of the Study:

• To synthesize a novel 3D nanoflower-like electrocatalyst (CFMO) for enhanced OER performance in AEMWE.
• To investigate the mechanism behind the improved catalytic activity induced by Fe-Co substitution.

Main Methods:

• One-step synthesis of a 3D nanoflower-like cobalt-iron oxide material (CFMO).
• Electrochemical characterization including OER performance testing (overpotential, stability).
• In situ characterization and first-principles calculations to elucidate the reaction mechanism.

Main Results:

• The optimized CFMO-2 electrocatalyst achieved an overpotential of 217 mV at 10 mA/cm² with excellent stability (>1000 h).
• The Fe-Co substitution induced a localized oxide path mechanism (LOPM), facilitating direct O-O radical coupling.
• An AEMWE system using CFMO-2 operated at 1.65 V for 1 A/cm², outperforming noble metal catalysts.

Conclusions:

• The novel LOPM mechanism significantly reduces energy barriers for OER.
• CFMO-2 demonstrates high efficiency and stability, offering a promising non-noble metal alternative for AEMWE.
• This work provides insights into designing advanced electrocatalysts for efficient water electrolysis.