Synergistic Catalytic Sites in High-Entropy Metal Hydroxide Organic Framework for Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• High-performance electrocatalysts are essential for efficient water electrolysis.
• Developing durable, cost-effective catalysts is a key challenge.
• High-entropy materials offer unique properties for catalytic applications.

Purpose of the Study:

• To synthesize and characterize novel high-entropy metal hydroxide organic frameworks (HE-MHOFs).
• To evaluate the electrocatalytic performance of HE-MHOFs for the oxygen evolution reaction (OER).
• To investigate the potential of HE-MHOFs as a sustainable alternative to precious metal catalysts.

Main Methods:

• Solvothermal synthesis of HE-MHOFs.
• Electrochemical testing for OER performance and durability.
• Ab initio calculations and operando X-ray absorption spectroscopy (XAS) for mechanistic studies.

Main Results:

• HE-MHOF demonstrated excellent OER activity, reaching 100 mA cm⁻² at ≈1.64 V_RHE.
• Exceptional durability was observed, maintaining 10 mA cm⁻² for over 100 hours.
• HE-MHOF outperformed precious metal catalysts, despite lower noble metal content.

Conclusions:

• High-entropy MOFs are promising noble metal-free electrocatalysts for OER.
• HE-MHOFs reduce reliance on precious metals and lower costs for water electrolysis.
• The study elucidates the multifaceted OER mechanism facilitated by high-entropy active sites.