Self-healing Cu single-atom catalyst for high-performance electrocatalytic CO₂ methanation.

Area of Science:

• Catalysis
• Materials Science
• Electrochemistry

Background:

• Atmospheric carbon dioxide (CO2) emissions pose a significant environmental challenge.
• Developing efficient catalysts for CO2 conversion is crucial for sustainability.
• Single-atom catalysts (SACs) offer high activity but often suffer from stability issues.

Purpose of the Study:

• To design a self-healing single-atom catalyst for enhanced CO2-to-methane conversion.
• To investigate the dynamic structural reconstruction of the catalyst under electrochemical conditions.
• To improve the stability and scalability of single-atom catalysts for industrial applications.

Main Methods:

• Fabrication of a self-healing copper single-atom (SA) catalyst with adjacent ZrO2 clusters.
• Electrochemical characterization including CO2-to-methane conversion measurements.
• In situ Raman and X-ray absorption fine structure (XAFS) spectroscopy to study dynamic reconstruction.
• Density functional theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

• A hybrid Cu-N/O structure formed via self-healing of Cu-N bonds.
• Dynamic reconstruction from CuN4 to CuN1O2 coordination environment observed.
• Significantly enhanced CO2-to-CH4 conversion efficiency (up to 87.06%) compared to pristine catalysts.
• Excellent stability with <3% activity decay over 25 hours in a membrane electrode assembly (MEA) electrolyzer.

Conclusions:

• The self-healing mechanism effectively reconstructs the catalyst's coordination environment, enhancing performance.
• The novel Cu-N/O catalyst demonstrates superior activity and stability for CO2 reduction.
• This strategy offers a promising pathway for developing robust and scalable single-atom catalysts for industrial CO2 utilization.