Enhancing CO₂ Electroreduction with the Metal-Oxide Interface.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical CO₂ reduction reaction (CO₂RR) is crucial for converting CO₂ into valuable products.
• Current CO₂RR catalysts, primarily transition metals, face challenges in efficiency and selectivity.
• Strategies to improve CO₂RR involve catalyst modification and electrolyte optimization.

Purpose of the Study:

• To investigate the enhancement of CO₂RR by constructing metal-oxide interfaces.
• To explore the catalytic activity and Faradaic efficiency of Au-CeO_x for CO₂RR.
• To demonstrate the generality of the interface strategy for CO₂RR enhancement.

Main Methods:

• Fabrication and characterization of Au-CeO_x and Ag-CeO_x interfaces.
• In situ scanning tunneling microscopy (STM) and synchrotron-radiation photoemission spectroscopy (SRPES) for interface analysis.
• Density functional theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

• Au-CeO_x exhibits significantly higher activity and Faradaic efficiency for CO₂RR compared to individual Au or CeO_x.
• The Au-CeO_x interface enhances CO₂ adsorption and activation, further promoted by hydroxyl groups.
• Ag-CeO_x also demonstrates interface-enhanced CO₂RR, confirming the strategy's broad applicability.

Conclusions:

• The metal-oxide interface is a highly effective strategy for boosting CO₂RR performance.
• Synergy between Au and CeO_x at the interface facilitates CO₂ activation and stabilizes the key *COOH intermediate.
• This interface-engineering approach offers a promising route for developing efficient electrocatalysts for CO₂ conversion.