Tuning Cu-Cu Spacing in Single-Atomic Layer Cu Catalysts for Efficient and Stable CO₂-To-C₂H₄ Electroreduction

Area of Science:

• Catalysis
• Materials Science
• Electrochemistry

Background:

• Efficient conversion of carbon dioxide (CO2) to multi-carbon (C2+) products is crucial for sustainable energy but limited by slow C─C coupling kinetics and poor selectivity.
• Single-atom catalysts (SACs) show promise but lack contiguous active sites, hindering C─C bond formation.

Purpose of the Study:

• To design and investigate an innovative 2D copper single-atomic-layer catalyst (SAC) on an amorphous carbon substrate.
• To enhance C─C coupling and selectivity for C2+ products in CO2 electroreduction.
• To elucidate the role of precisely controlled active site spacing in catalytic performance.

Main Methods:

• Fabrication of an isotropic 2D Cu single-atomic-layer catalyst anchored on amorphous carbon.
• Electrochemical CO2 reduction experiments to evaluate catalytic performance.
• Characterization of catalyst structure and active species (Cuδ+).

Main Results:

• The catalyst stabilized Cuδ+ species with tunable Cu-Cu spacing (2.35 Å), matching the C─C bond length of ethylene (C2H4).
• Achieved a high Faradaic efficiency of 78.6% for C2H4 production at -0.8 V vs RHE.
• Demonstrated excellent stability over 120 hours of operation.

Conclusions:

• Spatially controlled active sites significantly impact multi-step catalytic reactions like CO2 conversion.
• The developed 2D Cu SAC represents a significant advancement in CO2 electroreduction technology.
• This work offers potential for sustainable carbon utilization and addresses global energy transition challenges.