Steering surface reconstruction of copper with electrolyte additives for CO₂ electroreduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Metallic copper (Cu) catalysts are crucial for electrocatalytic CO2 reduction to valuable hydrocarbons, aiding carbon neutrality.
• Uncontrolled surface reconstruction of Cu during electrocatalysis often hinders optimal performance.

Purpose of the Study:

• To develop a strategy for guiding the surface reconstruction of copper catalysts in a favorable direction.
• To enhance the electrocatalytic performance of copper for CO2 reduction.

Main Methods:

• Utilizing ethylenediamine tetramethylenephosphonic acid as an electrolyte additive to control surface reconstruction.
• Employing commercial polycrystalline copper as the catalyst.
• Conducting experiments in an alkaline flow cell.

Main Results:

• Achieved a stable methane (CH4) Faradaic efficiency of 64%.
• Obtained a partial current density of 192 mA cm-2 for CH4 production.
• Demonstrated a CO2-to-CH4 conversion rate of 0.25 µmol cm-2 s-1.

Conclusions:

• Controlled surface reconstruction via electrolyte additives offers a promising route to high-performance electrocatalysts.
• This approach significantly improves CO2 electroreduction to CH4 using copper catalysts.
• The study provides a new perspective for designing electrocatalysts through electrochemical reconstruction.