Selective Electrochemical Conversion of CO₂ into Methane on Ag-Decorated Copper Microsphere

Area of Science:

• Materials Science and Engineering
• Electrochemistry
• Catalysis

Background:

• Copper (Cu) based catalysts are explored for carbon dioxide (CO2) electroreduction.
• Improving selectivity and efficiency of CO2 reduction to methane (CH4) remains a challenge.

Purpose of the Study:

• To synthesize and characterize silver-decorated copper microspheres (Ag/Cu) for enhanced CO2 electroreduction.
• To investigate the impact of silver nanoparticle (Ag NP) decoration on the electrochemical performance and selectivity of Cu microspheres for CH4 production.

Main Methods:

• Hydrothermal synthesis of copper microspheres.
• Photoreduction of silver ions to form sub-100 nm Ag nanoparticles on Cu microsphere surfaces.
• Electrochemical characterization of CO2 reduction performance.

Main Results:

• Silver nanoparticles (Ag NPs) successfully anchored on Cu microspheres.
• Ag/Cu microspheres exhibited significantly enhanced electrochemical performance, including lower charge transfer resistance and improved conductivity.
• The faradaic efficiency for methane (CH4) production over Ag/Cu microspheres reached 70.94%, nearly double that of bare Cu microspheres (44%).

Conclusions:

• Silver decoration enhances the catalytic properties, stability, and selectivity of copper microspheres for CO2 electroreduction to CH4.
• The enhanced performance is attributed to improved conductivity and increased active sites provided by the Ag NPs.
• Ag/Cu microspheres represent a promising catalyst for efficient and selective methane production from CO2.