A Monolithic High-Entropy Aerogel Anode for Stable and Low-Overpotential Oxygen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is critical for renewable energy technologies but faces challenges due to slow kinetics and mass transport limitations at high current densities.
• Developing efficient electrocatalysts is essential for overcoming these hurdles in large-scale energy applications.

Purpose of the Study:

• To design and develop a high-entropy monolithic aerogel (HE-AG) electrode for enhanced oxygen evolution reaction (OER) performance.
• To investigate the structure-property relationships governing the catalytic activity of the HE-AG electrode.

Main Methods:

• Fabrication of a high-entropy monolithic aerogel (HE-AG) electrode.
• Electrochemical characterization including OER performance testing at high current densities.
• Advanced structural analysis (e.g., X-ray diffraction, electron microscopy) and theoretical calculations (e.g., DFT).
• In situ Raman spectroscopy to probe dynamic changes during catalysis.

Main Results:

• The HE-AG electrode exhibited outstanding OER performance, reaching 500 mA cm⁻² at a low overpotential of 208 mV.
• Structural and theoretical studies revealed that the diverse electronic environment in HE-AG enables independent modulation of OER elementary steps.
• In situ Raman spectroscopy indicated that Cr and V leaching facilitates electrochemical reconstruction to active oxyhydroxides.

Conclusions:

• The HE-AG electrode offers a promising solution for efficient OER catalysis, addressing key limitations in energy transition technologies.
• The study highlights the importance of electronic environmental diversity and electrochemical reconstruction for catalyst design.
• The developed synergistic strategy provides a general design principle for heterogeneous catalysis.