Promoting Ethylene Selectivity from CO₂ Electroreduction on CuO Supported onto CO₂ Capture Materials

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Copper (Cu) catalysts are unique for CO2 electroreduction but lack selectivity.
• High CO2 pressure can improve Cu catalyst performance but is impractical.
• Developing selective and efficient CO2 reduction catalysts is crucial for carbon utilization.

Purpose of the Study:

• To enhance the selectivity of Cu catalysts for C2H4 production during CO2 electroreduction.
• To investigate the use of CO2 capture materials as supports for Cu catalysts at ambient pressure.
• To understand the relationship between CO2 capture capacity and catalytic performance.

Main Methods:

• Synthesis of N-doped carbon (NxC) supports via high-temperature carbonization of melamine and l-lysine.
• Preparation of CuO/NxC catalysts and control of NxC properties by adjusting carbonization temperature (600-800°C).
• Electrochemical evaluation of CuO/NxC catalysts for CO2 reduction, measuring C2H4 faradaic efficiency.

Main Results:

• NxC supports exhibited CO2 uptake capacity dependent on microporous area and pyridinic N content.
• CuO/NxC catalysts achieved significantly higher C2H4 faradaic efficiency (36%) compared to controls (19-20%).
• A linear correlation was observed between C2H4 selectivity and the CO2 uptake capacity of the supports.

Conclusions:

• CO2 capture materials as supports can create localized high CO2 concentrations, enhancing CO intermediate coverage.
• This strategy promotes CO coupling for improved C2H4 formation, offering a promising route for efficient CO2 electroreduction.
• Pairing Cu catalysts with CO2 capture supports is an effective approach for designing advanced electrocatalysts.