Ag Stabilized Cu⁺/Cu⁰ Interface Catalysts for Enhanced CO₂ Electroreduction to C₂₊ Products at Ampere Level Current...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical carbon dioxide reduction reaction (CO2RR) to multicarbon (C2+) products is crucial for industrial applications but faces challenges in achieving high current density, Faradaic efficiency (FE), and stability.
• Existing catalysts often struggle to meet the demanding requirements for efficient and stable CO2RR.

Purpose of the Study:

• To develop a highly efficient and stable catalyst for electrochemical CO2RR to C2+ products at industrially relevant current densities.
• To investigate the catalytic mechanism at the interface of the developed catalyst.

Main Methods:

• Synthesis and characterization of a 5.6 atom % Ag/Cu2O-Cu catalyst.
• Electrochemical evaluation of CO2RR performance in 1 M KOH electrolyte.
• In situ Raman spectrometry and density functional theory (DFT) calculations to elucidate the reaction mechanism.

Main Results:

• The 5.6 atom % Ag/Cu2O-Cu catalyst achieved a Faradaic efficiency of 76.5 ± 1.2% for C2+ products at a high current density of 1.0 A/cm2.
• The catalyst demonstrated stable CO2 electrolysis at 0.50 A/cm2 for 20 hours in a flow cell.
• In situ studies and DFT calculations revealed that steady Ag/Cu+/Cu0 interfaces promote CO2-to-C2+ conversion by optimizing the energy barrier for *CO intermediate formation and dimerization.

Conclusions:

• The developed Ag/Cu2O-Cu catalyst, featuring abundant and steady Ag/Cu+/Cu0 interfaces, significantly enhances the activity, selectivity, and stability of CO2 electroreduction to C2+ products.
• The synergistic effects at these heterogeneous interfaces facilitate a tandem reaction pathway involving *COOH, *CO, and *OCCO intermediates, paving the way for practical CO2RR applications.