Metal-organic double layer to stabilize selective multi-carbon electrosynthesis

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Stable operation of gas diffusion electrodes is critical for industrial-scale electrochemical CO2 reduction (eCO2R).
• Existing methods face challenges in maintaining long-term electrolytic stability.
• Understanding the triphasic interface is key to improving eCO2R performance.

Purpose of the Study:

• To enhance the electrolytic stability of copper-based gas diffusion electrodes for eCO2R.
• To introduce a Metal-Organic Double Layer (MODL) scheme for improved electrode performance.
• To investigate the molecular-level mechanisms governing interfacial properties in eCO2R.

Main Methods:

• Electrospinning a polycationic sheath to shield copper-coated gas diffusion electrodes.
• Fabricating electrodes with the proposed MODL scheme.
• Conducting electrochemical performance tests in alkaline flow cells and membrane electrode assemblies.
• Performing mechanistic investigations to understand interfacial effects.

Main Results:

• The fabricated electrode achieved a multi-carbon Faradaic efficiency of 91.2% ± 3.8%.
• Demonstrated operational stability exceeding 300 hours at 300 mA cm⁻².
• Achieved over 50% ethylene Faradaic efficiency at 200 mA cm⁻² in a membrane electrode assembly with pure water.
• Unveiled that MODL tailors local electric fields and interfacial water structure.

Conclusions:

• The MODL scheme significantly enhances the stability and efficiency of eCO2R.
• Molecular-level redesign of the electric double layer offers precise control over electrostatic characteristics and chemical microenvironments.
• This approach enables highly efficient and stable production of multi-carbon products via sustainable electrolysis.