Saturated Coordination LuN₆ Defect Sites for Highly Efficient Electroreduction of CO₂

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Metal single-atom catalysts (M-N-C) often contain structural defects.
• Understanding the interplay between single atoms and defects is crucial for optimizing catalytic activity.
• Rare-earth elements offer unique electronic properties for catalyst design.

Purpose of the Study:

• To synthesize and characterize a novel single-atom lutetium (Lu) catalyst supported on nitrogen-carbon (N-C).
• To investigate the structure-activity relationship of Lu-N-C catalysts, focusing on the role of intrinsic defects.
• To evaluate the catalyst's performance in carbon dioxide reduction reactions.

Main Methods:

• Synthesis of lutetium-based single-atom catalyst on N-C support via pyrolysis.
• Structural analysis using advanced techniques.
• Density functional theory (DFT) simulations to understand defect formation and active sites.
• Electrochemical evaluation of CO2 reduction reaction in KHCO3 electrolyte.

Main Results:

• Successful synthesis of a Lu-N-C single-atom catalyst with a thermodynamically favorable LuN6 defect site.
• Demonstrated improved CO2 capture and activation due to K+ ion interaction with defective sites.
• Achieved a high Faradaic efficiency of 95.1% for CO production at 18.2 mA cm-2.

Conclusions:

• The study highlights the favorable formation of LuN6 defect sites in Lu-N-C catalysts.
• Defect sites enhance CO2 capture and activation, improving catalyst conductivity and performance.
• This work provides valuable insights into rare-earth-based nitrogen-carbon catalysts for energy applications.