Less-Coordinated Atomic Copper-Dimer Boosted Carbon-Carbon Coupling During Electrochemical CO₂ Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical carbon dioxide reduction (eCO2 RR) is a promising pathway for sustainable chemical production.
• Metal-organic frameworks (MOFs) offer tunable structures for catalytic applications.
• Controlling the coordination environment of metal centers is crucial for optimizing catalytic performance.

Purpose of the Study:

• To synthesize and characterize a novel MOF featuring less-coordinated copper dimers.
• To investigate the electrochemical CO2 reduction performance of the designed MOF.
• To elucidate the mechanism underlying the enhanced catalytic activity and selectivity.

Main Methods:

• Synthesis and characterization of a copper dimer-containing MOF.
• Electrochemical CO2 reduction experiments.
• In situ characterization techniques (e.g., X-ray absorption spectroscopy).
• Density functional theory (DFT) calculations.

Main Results:

• The MOF with copper dimers exhibited superior eCO2 RR performance compared to MOFs with copper monomers.
• Achieved a current density of 0.9 A cm⁻² and 71% Faradaic efficiency for C2 products.
• Identified stable adsorption of *CO intermediates and favored dimerization via *CH2CHO on the less-coordinated Cu dimers.
• Demonstrated that highly unsaturated dual-atomic Cu sites facilitate C-C coupling.

Conclusions:

• Less-coordinated copper dimers in MOFs significantly enhance electrochemical CO2 reduction to C2 products.
• The unique electronic structure of the Cu dimers promotes efficient CO2 activation and C-C bond formation.
• This study provides insights into designing advanced MOFs for selective CO2 conversion.