Highly Enhanced Chloride Adsorption Mediates Efficient Neutral CO₂ Electroreduction over a Dual-Phase Copper Catalyst

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrocatalytic carbon dioxide reduction (CO2R) in neutral electrolytes faces challenges with multicarbon selectivity and reaction rates due to kinetic limitations in the CO-CO coupling step.
• Carbonate formation in neutral electrolytes leads to energy and carbon losses, necessitating catalysts that operate efficiently under these conditions.

Purpose of the Study:

• To develop a robust electrocatalyst for efficient multicarbon production from CO2R in neutral electrolytes.
• To enhance the kinetics of the critical CO-CO coupling step for improved selectivity and reaction rates.

Main Methods:

• Fabrication of a dual-phase copper-based catalyst with abundant Cu(I) sites at amorphous-nanocrystalline interfaces.
• Electrochemical characterization in neutral potassium chloride electrolyte (pH ~6.6).
• Assessment of catalyst stability and performance at industrially relevant current densities.

Main Results:

• The dual-phase copper catalyst demonstrated enhanced chloride-specific adsorption and mediated local CO coverage, improving CO-CO coupling kinetics.
• Achieved high Faradaic efficiency of 81% for multicarbon products during CO2R.
• Reached a partial current density of 322 mA/cm² with excellent stability over 45 hours of operation.

Conclusions:

• The designed dual-phase copper catalyst effectively overcomes kinetic limitations in neutral electrolyte CO2R.
• This catalyst design strategy offers a promising pathway for efficient and stable multicarbon production relevant to commercial CO2 electrolysis.