Triple-Phase Interface Engineered Hierarchical Porous Electrode for CO₂ Electroreduction to Formate.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical reduction of carbon dioxide (CO2) is crucial for carbon neutrality but faces challenges in selectivity and current density.
• Efficient CO2 reduction requires optimized electrodes for stable triple-phase contact (CO2, electrolyte, active sites).

Purpose of the Study:

• To develop a novel electrode for highly selective and efficient electrochemical CO2 reduction.
• To investigate the role of triple-phase interface engineering in enhancing CO2 reduction performance.

Main Methods:

• Fabrication of a hierarchical porous electrode using bismuth nanosheet arrays on copper foam.
• Surface modification with trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane.
• Electrochemical testing in an H-cell and theoretical calculations.

Main Results:

• Achieved formate selectivity exceeding 90% over a wide potential range.
• Reached a partial current density of over -90 mA cm⁻².
• Demonstrated superior long-term stability for the modified electrode.

Conclusions:

• The engineered electrode effectively enhances electrochemical CO2 reduction through optimized triple-phase interface.
• Surface modification and hierarchical morphology contribute to high selectivity, efficiency, and stability.
• Theoretical calculations confirm improved activation pathways for formate production.