A carbon-based single-atom Cu electrocatalyst for efficient conversion of CO₂ to carbon products

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical reduction of carbon dioxide (CO2) is crucial for sustainable energy and chemical production.
• Challenges include competing hydrogen evolution, high activation energy barriers, and inefficient C-C coupling.
• Developing selective and efficient electrocatalysts for CO2 to C1 and C2 products remains a significant hurdle.

Purpose of the Study:

• To design and investigate a novel N-doped carbon-based single-atom copper electrocatalyst (Cu-N4/C) for efficient CO2 electroreduction.
• To elucidate the reaction mechanism and identify active sites responsible for high selectivity towards carbon products.
• To assess the catalyst's efficiency, selectivity, and stability for CO2 conversion.

Main Methods:

• Synthesis of an N-doped carbon-supported single-atom copper catalyst (Cu-N4/C).
• Electrochemical characterization including cyclic voltammetry and chronoamperometry.
• In situ infrared spectroscopy to identify reaction intermediates.
• Faradaic efficiency and product selectivity analysis.

Main Results:

• The Cu-N4/C catalyst achieved a high total Faraday efficiency of 94.67% for CO2 electroreduction to CO and ethanol.
• Ethanol selectivity reached 53.11%, indicating high C2 product formation.
• The catalyst exhibited excellent stability, maintaining performance for over 16 hours.
• In situ infrared spectroscopy revealed key intermediates (*COB, *OCH2, *CO-*OCH2, OC2H5) promoting CO and ethanol generation.

Conclusions:

• The designed Cu-N4/C single-atom catalyst effectively promotes simultaneous electroreduction of CO2 to C1 and C2 products.
• The catalyst's structure and the identified intermediates are crucial for achieving high carbon product efficiency and selectivity.
• This work provides insights into the active sites and reaction pathways, guiding the rational design of future CO2 electroreduction catalysts.