Copper Nanocubes for CO₂ Reduction in Gas Diffusion Electrodes

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Carbon dioxide (CO2) electroreduction is a key technology for sustainable energy and chemical production.
• Catalyst surface structure and local electrochemical environment critically influence CO2 electroreduction performance.
• Developing efficient electrocatalysts is crucial for mitigating global energy and sustainability challenges.

Purpose of the Study:

• To investigate the impact of copper (Cu) nanoparticle shape on CO2 electroreduction.
• To explore the role of {100} facets in Cu nanocube electrocatalysts.
• To understand the combined effects of catalyst morphology and electrolyte alkalinity on CO2 electroreduction.

Main Methods:

• Synthesis of Cu nanocubes (~70 nm) with preferential {100} facet exposure.
• Utilized gas-diffusion electrodes (GDEs) for CO2 electroreduction experiments.
• Employed flowing alkaline catholytes with varying KOH concentrations.

Main Results:

• Cu nanocubes exhibited significantly enhanced catalytic activity and selectivity for CO2 reduction compared to Cu nanospheres.
• Optimized Cu nanocubes achieved 60% Faradaic efficiency for ethylene (C2H4) production.
• A partial current density of 144 mA/cm2 towards ethylene was reached with Cu nanocubes.
• Electrocatalytic performance was sensitive to KOH electrolyte concentration.

Conclusions:

• Copper nanoparticle shape, specifically nanocubes exposing {100} facets, substantially improves CO2 electroreduction.
• The enhanced performance is attributed to synergistic effects of surface structure and electrolyte alkalinity.
• This study provides insights into designing advanced electrocatalysts for efficient CO2 conversion into valuable products like ethylene.