Probing the Active Surface Sites for CO Reduction on Oxide-Derived Copper Electrocatalysts

Area of Science:

• Electrochemistry
• Materials Science
• Surface Science

Background:

• Electrocatalytic CO2 reduction is crucial for sustainable chemical synthesis.
• Oxide-derived copper (OD-Cu) shows promise for CO electroreduction, but active sites remain unclear.

Purpose of the Study:

• To investigate the correlation between surface features and CO electroreduction activity on OD-Cu.
• To identify the specific surface sites responsible for efficient CO conversion.

Main Methods:

• Preparation of OD-Cu electrodes via H2 reduction of Cu2O.
• Electrochemical CO reduction experiments.
• Temperature-programmed desorption (TPD) of CO to analyze surface binding sites.

Main Results:

• OD-Cu electrodes achieved nearly 50% Faradaic efficiency for CO to acetate and ethanol.
• TPD revealed strong CO binding sites distinct from polycrystalline copper.
• Annealing OD-Cu at 350 °C drastically reduced activity and strong CO binding sites.

Conclusions:

• Metastable surface features with strong CO binding sites are critical for efficient CO electroreduction on OD-Cu.
• Grain boundaries likely support these active sites.
• Understanding these sites is essential for designing improved electrocatalysts for CO conversion.