CO₂ electroreduction to ethylene via hydroxide-mediated copper catalysis at an abrupt interface

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Carbon dioxide (CO2) electroreduction is a promising route for producing valuable chemicals like ethylene.
• Current systems face limitations in conversion efficiency, production rates, and catalyst stability.

Purpose of the Study:

• To develop a highly efficient and stable copper electrocatalyst for CO2 to ethylene conversion.
• To investigate the role of alkaline electrolytes and reaction interfaces in enhancing electroreduction.

Main Methods:

• Utilized a copper electrocatalyst at an abrupt reaction interface in an alkaline electrolyte.
• Employed a polymer-based gas diffusion layer to stabilize the reaction interface.
• Operated at a potential of -0.55 volts versus a reversible hydrogen electrode (RHE).

Main Results:

• Achieved 70% faradaic efficiency for CO2 to ethylene conversion.
• Identified that hydroxide ions lower activation energy barriers for CO2 reduction and CO-CO coupling.
• Observed ethylene evolution onset at -0.165 V vs RHE in 10 M KOH.
• Demonstrated sustained ethylene selectivity for 150 operating hours.

Conclusions:

• The developed copper electrocatalyst system significantly improves CO2 electroreduction efficiency and selectivity for ethylene.
• The unique reaction interface and electrolyte conditions are key to enhanced performance.
• The polymer-based gas diffusion layer ensures operational stability, paving the way for industrial applications.