Asymmetrically Coordinated Cu Dual-Atom-Sites Enables Selective CO₂ Electroreduction to Ethanol

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical reduction of CO2 (CO2RR) is crucial for carbon-neutral recycling, particularly for producing C2+ liquid fuels.
• Controlling selectivity in CO2RR remains a significant challenge due to complex multi-electron proton transfer processes.

Purpose of the Study:

• To synthesize and optimize Cu atomic dispersed catalysts for enhanced CO2RR selectivity.
• To investigate the mechanism behind high ethanol selectivity using a novel catalyst design.

Main Methods:

• Synthesis of a series of Cu atomic dispersed catalysts with varied coordination structures.
• Electrochemical testing in H-Cell and Flow-Cell configurations.
• In situ experiments and theoretical calculations to elucidate reaction mechanisms.

Main Results:

• A Cu2-SNC catalyst with asymmetrical CuN2-CuNS sites achieved high ethanol selectivity (62.6% FE at -0.8 V in H-Cell, 60.2% FE at 0.9 V in Flow-Cell).
• The nest-like structure of Cu2-SNC improved mass transfer and product selectivity.
• Sulfur atoms were found to weaken Cu-carbon bonding, promoting ethanol formation pathway.

Conclusions:

• The rational design of asymmetrically coordinated single, dual, or tri-atom catalysts is a promising strategy for CO2RR.
• Cu2-SNC is a candidate material for efficient and selective CO2RR to ethanol.