Enhanced Interface with Strong Charge Delocalization toward Ultralow Overpotential CO₂ Electroreduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Interfacial engineering is key for efficient electrochemical carbon dioxide reduction (CO2RR).
• Weak interactions and instability at interfaces limit CO2RR performance.
• A pure interface effect requires a well-defined system to isolate interfacial contributions.

Purpose of the Study:

• To investigate the pure interface effect on CO2RR by embedding silver nanoclusters (Ag NCs) onto porous ceria nanospheres (CeO2 NSs).
• To enhance the performance of CO2RR catalysts by optimizing the Ag-CeO2 interface.
• To understand the mechanism behind interface-induced performance improvements.

Main Methods:

• Synthesis of Ag nanoclusters embedded onto CeO2 nanospheres (Ag NCs@CeO2 NSs).
• Electrochemical characterization of CO2RR performance (current density, Faraday efficiency, overpotential).
• Computational studies (free energy and differential charge calculations) and X-ray photoelectron spectroscopy (XPS) for mechanistic analysis.

Main Results:

• Ag NCs@CeO2 NSs exhibited significantly enhanced current density, Faraday efficiency (FE), and energy efficiency compared to individual components and dispersed Ag NCs.
• Achieved a high CO FE of over 70.0% at an ultralow overpotential (η) of 146 mV.
• Demonstrated superior performance attributed to the Ag-CeO2 interface.

Conclusions:

• The Ag-CeO2 pure interface effectively promotes CO2RR to CO at lower overpotentials.
• Interface-induced charge delocalization enhances electron transfer to the *COOH intermediate, lowering the rate-determining step barrier.
• This work highlights the critical role of well-designed interfaces in advancing CO2RR catalysis.