Sn-Induced Stable Cu⁺ in Cu₂O/Cu₆Sn₅ Interface System for Stabilizing *OCHO in CO₂-to-Formate Electroreduction.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Stable Cu+ species are vital for efficient CO2 electroreduction reactions.
• Developing advanced catalysts for CO2-to-formate conversion is critical for carbon utilization.

Purpose of the Study:

• To construct a Sn-induced Cu2O/CuSn interface with stable Cu+ for CO2 electroreduction.
• To investigate the catalytic performance and reaction mechanism for CO2-to-formate conversion.

Main Methods:

• Fabrication of a Cu2O/CuSn interface system.
• Electrochemical testing including Faradaic efficiency and partial current density measurements.
• Density Functional Theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

• Cu2O/CuSn achieved 91.3% Faradaic efficiency for formate at -1.1 V vs RHE.
• High formate selectivity (>80%) was maintained over a wide potential range (-0.8 to -1.2 V vs RHE).
• DFT calculations revealed enhanced CO2 adsorption and a stabilized *OCHO intermediate.

Conclusions:

• The Cu2O/CuSn interface effectively promotes CO2 electroreduction to formate.
• Synergistic effects between Cu2O and CuSn alloy enhance catalytic activity and suppress hydrogen evolution.
• The stable Cu+ species and modulated electronic structure are key to the catalyst's performance.