Modifying the Redox Properties of Co₃O₄ for Enhanced Acidic Oxygen Evolution by Lattice Stretching

Area of Science:

• Materials Science
• Electrochemistry
• Green Chemistry

Background:

• Proton exchange membrane water electrolysis is key to the green hydrogen economy.
• Current technologies rely heavily on expensive noble metal catalysts.
• Developing cost-effective alternatives is crucial for widespread adoption.

Purpose of the Study:

• To develop a low-cost cobalt oxide (Co3O4) catalyst for enhanced oxygen evolution reaction (OER) performance in acidic media.
• To investigate the effect of lattice tensile strain on the catalytic properties of Co3O4.
• To provide a stable and efficient alternative to noble metal catalysts for water electrolysis.

Main Methods:

• Potassium bromide-assisted thermal decomposition to synthesize Co3O4 catalyst.
• Inducing lattice tensile strain to modulate cobalt's redox properties.
• In situ differential electrochemical mass spectrometry (DEMS) and cyclic voltammetry for mechanistic studies.

Main Results:

• The synthesized Co3O4 catalyst demonstrated excellent OER performance in acidic media.
• Achieved a low overpotential of 377 mV at 10 mA·cm-2 current density.
• Maintained stable operation for 150 hours.
• Lattice tensile strain was confirmed to alter the redox mechanism, promoting the oxide pathway.

Conclusions:

• The Co3O4 catalyst with lattice tensile strain offers superior activity and stability for OER.
• This development presents a promising, cost-effective solution for green hydrogen production via water electrolysis.
• The findings pave the way for broader application of non-noble metal catalysts in sustainable energy technologies.