Tensile-Strained Cu Penetration Electrode Boosts Asymmetric C-C Coupling for Ampere-Level CO₂-to-C₂₊ Reduction in...

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Chemistry

Background:

• Sustainable synthesis of multicarbon (C2+) products via CO2 electroreduction is challenging due to low current density and efficiency.
• Existing methods struggle to achieve high selectivity and efficiency for C2+ products, limiting practical applications.

Purpose of the Study:

• To develop a highly efficient electrocatalyst for CO2 electroreduction to C2+ products.
• To investigate the role of electrolyte composition and electrode architecture in enhancing C2+ selectivity and current density.
• To achieve high performance in both neutral and strongly acidic electrolytes.

Main Methods:

• Fabrication of a hierarchical copper hollow-fiber penetration electrode (HPE).
• Electrochemical reduction of CO2 in neutral and acidic (pH=1) electrolytes with varying K+ and H+ concentrations.
• Optimization of CO2 flow rate and electrolyte conditions.
• Characterization using experimental measurements and density functional theory (DFT) simulations.

Main Results:

• Achieved ampere-level high efficiency for CO2 electroreduction to C2+ products.
• Demonstrated a faradaic efficiency of 84.5% and partial current density of 3.1 A/cm2 for C2+ products in acidic media (pH=1).
• Obtained a single-pass carbon efficiency of 81.5% and stable electrolysis for 240 hours.
• Identified that high K+ concentration suppresses hydrogen evolution and promotes C-C coupling.

Conclusions:

• The hierarchical Cu HPE effectively promotes CO2 electroreduction to C2+ products with high efficiency and selectivity.
• Tensile-strained Cu HPE enhances asymmetric C-C coupling, steering selectivity and activity.
• The developed system offers a promising pathway for sustainable production of C2+ chemicals.