Efficient Electrochemical CO₂ Reduction Using AgN₃ Single-Atom Sites Embedded in Free-Standing Electrodes for Flow...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical reduction of CO2 is crucial for carbon utilization but hindered by catalyst limitations.
• Existing catalysts suffer from low activity, poor selectivity, and insufficient stability.

Purpose of the Study:

• To fabricate and evaluate free-standing silver single-atom catalysts (Ag SACs) for efficient CO2 electroreduction.
• To enhance CO2 conversion to carbon monoxide (CO) at high current densities.

Main Methods:

• Fabrication of free-standing silver single-atom catalysts (Ag SACs) with Ag-N3 active sites.
• Electrochemical evaluation of catalytic activity and stability at 100 mA cm-2 in a bicarbonate electrolyzer.
• Density functional theory (DFT) calculations to investigate reaction mechanisms and active site performance.

Main Results:

• Ag SACs demonstrated efficient and stable CO2 electroreduction to CO at high current densities.
• The Ag-N3 active site significantly lowered energy barriers for CO2 absorption and activation.
• DFT calculations confirmed the superior performance of Ag-N3 sites over Ag-Ag and Ag-Ni sites.

Conclusions:

• Free-standing Ag SACs offer enhanced efficiency and selectivity for CO2 electroreduction.
• The Ag-N3 active site is key to the improved catalytic performance.
• These findings advance CO2 reduction technologies for carbon utilization.