Defect-Driven Accelerated Reconstruction of Metal-Organic Frameworks Toward High-Performance Anion Exchange Membrane...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Metal-organic frameworks (MOFs) offer tunable structures for studying electrocatalysis.
• Developing efficient MOF-based oxygen evolution reaction (OER) catalysts is challenging due to limited control over framework defects and reconstruction.

Purpose of the Study:

• To develop a defect-engineering strategy for constructing highly efficient MOF-based OER catalysts.
• To investigate the role of framework defects in MOF reconstruction and OER activity.

Main Methods:

• Co-assembly of ferrocene ligand (Fc) and benzoic acid (BA) on nickel foam to create defect-rich NiFcBA-MOF.
• Electrochemical characterization of NiFcBA-MOF and defect-free NiFc-MOF under OER conditions.
• Testing NiFcBA-MOF as an anode in an anion-exchange membrane water electrolyzer.

Main Results:

• NiFcBA-MOF exhibits accelerated electrochemical activation and in situ transformation into active oxyhydroxides.
• NiFcBA-MOF requires a lower overpotential (270 mV) to reach 100 mA cm⁻² compared to NiFc-MOF (290 mV).
• NiFcBA-MOF demonstrates high performance in a water electrolyzer, achieving 1 A cm⁻² at 1.85 V and stable operation for 100 hours.

Conclusions:

• Rational defect engineering in MOFs can control reconstruction kinetics toward active oxyhydroxides.
• This approach provides a viable route for developing MOF-derived OER catalysts for water electrolyzers.
• Defect-rich NiFcBA-MOF shows superior OER performance and stability, outperforming defect-free counterparts.