Selective CO₂ electrolysis to CO using isolated antimony alloyed copper.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical reduction of carbon dioxide (CO2) to carbon monoxide (CO) is crucial for sustainable chemical production.
• Noble metals show high CO2-to-CO performance, but copper (Cu) catalysts face challenges with C-C coupling and byproduct formation.
• Scaling up CO2 electroreduction economically remains a significant hurdle.

Purpose of the Study:

• To develop a highly selective and efficient catalyst for CO2-to-CO conversion.
• To tune the catalytic properties of copper by alloying with antimony.
• To investigate the mechanism behind enhanced CO selectivity and production rates.

Main Methods:

• Synthesis of an antimony-copper single-atom alloy catalyst (Sb1Cu).
• Electrochemical testing to evaluate CO2 reduction performance, including Faradaic efficiency and partial current density.
• In situ spectroscopic measurements and theoretical simulations to elucidate the catalytic mechanism.

Main Results:

• The Sb1Cu catalyst achieved over 95% Faradaic efficiency for CO2-to-CO conversion.
• A partial current density of 452 mA cm⁻² with approximately 91% CO Faradaic efficiency was recorded.
• Negligible formation of C2+ products was observed, indicating high selectivity.

Conclusions:

• The atomic Sb-Cu interface in the Sb1Cu catalyst promotes CO2 adsorption and activation.
• Weakened binding of CO* intermediates at the Sb-Cu interface enhances CO selectivity and production rates.
• Sb1Cu represents a promising catalyst for efficient and selective electrochemical CO2 reduction to CO.