Ag Single Atoms Anchored on CeO₂ with Interfacial Oxygen Vacancies for Efficient CO₂ Electroreduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Silver single-atom catalysts (Ag SACs) show promise for CO2 electroreduction to CO.
• Achieving high current density and atom efficiency simultaneously remains a challenge.

Purpose of the Study:

• To develop a simple method for preparing highly efficient Ag SACs on CeO2.
• To investigate the catalytic performance and mechanism of the prepared Ag SACs for CO2RR.

Main Methods:

• In situ adsorption-reduction method to prepare Ag SACs on CeO2 (Ag1/CeO2).
• Electrochemical characterization in H-cells and flow cells.
• Density functional theory (DFT) calculations.

Main Results:

• Ag1/CeO2 catalysts exhibit strong metal-support interaction and interfacial oxygen vacancies.
• Achieved >95% CO faradaic efficiency over a wide potential range.
• Reached industrial-grade current density of 403 mA cm-2 with 97.2% FECO in flow cells.
• Turnover frequency of 50,310 h-1 at 99.5% FECO in H-cells.

Conclusions:

• The Ag1/CeO2 catalyst demonstrates superior performance in CO2 electroreduction.
• Interfacial oxygen vacancies and Ag-O-Ce3+ interfaces are key to enhanced activity.
• Synergistic effect between Ag and CeO2 activates CO2 adsorption and reduces reaction barriers.