Copper-Indium Binary Catalyst on a Gas Diffusion Electrode for High-Performance CO₂ Electrochemical Reduction with...

Area of Science:

• Catalysis
• Electrochemistry
• Materials Science

Background:

• Copper-indium (Cu-In) metallic hybrids show promise as non-noble catalysts for electrochemical CO2 reduction (eCO2R).
• Direct assembly of Cu-In catalysts with gas diffusion electrodes (GDEs) is crucial for high-performance eCO2R but remains a challenge.
• Achieving both high Faradaic efficiency (FE) and high current density in eCO2R requires optimized catalyst-electrode integration.

Purpose of the Study:

• To develop a GDE-combined Cu-In electrocatalyst using an in situ electrochemical spontaneous precipitation (ESP) method.
• To investigate the catalytic performance of the novel GDE-combined Cu-In electrocatalyst for selective CO2 reduction to CO.
• To demonstrate the potential for tunable syngas production by optimizing ESP conditions.

Main Methods:

• Utilized in situ electrochemical spontaneous precipitation (ESP) for the first time to prepare GDE-combined Cu-In electrocatalysts.
• Characterized the catalyst structure, revealing a nanoscale core-shell structure of polycrystalline CuO covered by an amorphous In(OH)3 interface.
• Employed a GDE flow cell with a 1 M KOH catholyte for electrochemical testing.

Main Results:

• Achieved higher than 90% Faradaic efficiency for CO production.
• Reached a current density of approximately 200 mA cm-2 at -1.17 V vs. RHE.
• Set a record CO yield efficiency of 3.05 mg min-1 (CO2/15 mL min-1 with a 2 cm2 electrode).
• Demonstrated tunable ratios of CO and H2 production by adjusting ESP conditions.

Conclusions:

• The developed GDE-combined Cu-In electrocatalyst enables highly selective and efficient electrochemical CO2 reduction to CO.
• The in situ ESP method provides a simple approach for constructing advanced catalytic interfaces.
• This work paves the way for novel catalytic interfaces with dual active centers for eCO2R and other electrochemical applications.