Smart Electrode Surfaces by Electrolyte Immobilization for Electrocatalytic CO₂ Conversion.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical CO2 reduction reaction (CO2RR) is crucial for sustainable chemistry.
• Catalyst performance is sensitive to the electrode/electrolyte interface electric field.
• Controlling this interface is key to optimizing CO2RR.

Purpose of the Study:

• To develop a novel method for controlling the electrode/electrolyte interface electric field.
• To enhance CO2 conversion to formate using an imidazolium cation organic layer.
• To investigate the stability and scalability of this modified electrode for CO2RR.

Main Methods:

• Covalent grafting of imidazolium cations onto a carbon electrode surface.
• Electrochemical CO2 reduction experiments in acidic aqueous solution using a flow cell.
• Density Functional Theory (DFT) calculations to study reaction mechanisms.
• Long-term electrolysis tests at industrially relevant current densities (100 mA cm-2).

Main Results:

• Imidazolium modification significantly favors CO2 to formate conversion.
• Hydrogen evolution reaction (HER) was suppressed, and cell voltage was reduced.
• High formate production rate of 4.6 gHCOO m-2 min-1 achieved.
• Stable formate production over 9000 C with no significant electrode degradation.

Conclusions:

• Imidazolium-modified electrodes offer a promising strategy for efficient and selective electrochemical CO2 reduction.
• The smart electrode surface concept is scalable and stable for practical CO2RR applications.
• This approach contributes to advancing carbon capture and utilization technologies.