Spatially Engineered Cu(II)-Containing Polyphosphazene-Based Catalysts Enable Electrochemical CO₂ Reduction to...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical reduction of carbon dioxide (CO2) to value-added products is crucial for sustainability.
• Low efficiency in carbon-carbon (C─C) coupling reactions limits selectivity and activity in CO2 electrocatalysis.

Purpose of the Study:

• To design a novel catalyst with precisely controlled dual catalytic centers for enhanced CO2 electroreduction.
• To improve the selectivity and efficiency of multi-carbon product formation from CO2.

Main Methods:

• Synthesis of a polyphosphazene network incorporating dendritic molecules and copper(II) porphyrin complexes.
• Formation of an ultrathin polymer sheath around carbon nanotubes with optimized spatial arrangement of dual-atom catalytic centers.
• Electrochemical evaluation of the catalyst's performance in CO2 reduction.

Main Results:

• Achieved precise supramolecular configuration with an optimized spatial distance of 3.8 Å between neighboring copper active sites.
• Demonstrated boosted C─C coupling reactions, leading to improved selectivity for ethanol (EtOH).
• Obtained a maximum Faradic efficiency (FEmax) of 61.1% for EtOH at -1.0 V over a broad potential window.

Conclusions:

• The developed polyphosphazene-based dual-atom catalyst effectively enhances C─C coupling for CO2 electroreduction.
• Precise control over the spatial distance of catalytic centers is a viable strategy for designing advanced single-atom electrocatalysts.
• This approach offers a promising pathway for efficient electrochemical synthesis of multi-carbon products from CO2.