Construction of Metal-N₂O₂ Sites on Poly(ionic liquid) for Highly Efficient Electrocatalytic CO₂ Reduction

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical CO2 conversion is crucial for sustainable energy.
• Developing efficient and selective catalysts remains a significant challenge.

Purpose of the Study:

• To fabricate and investigate atomically dispersed metal catalysts (Salen-PIL(Zn/Cu)) for electrochemical CO2-to-C1 conversion.
• To understand the influence of catalyst structure and properties on activity and selectivity.

Main Methods:

• Polymerization of a vinyl-decorated ionic liquid (IL) monomer with a Salen-M moiety.
• Characterization of atomically dispersed Salen-Zn/Cu complexes within a PIL skeleton.
• Electrochemical testing to evaluate CO2 reduction performance.

Main Results:

• Salen-Zn/Cu catalysts exhibited distinct electron transfer speeds, CO affinity, and H2O activation.
• Catalyst performance was influenced by CO2 radical anion formation, H2O activation, and pH tolerance.
• Hydrophobic ILs improved CO2 reduction selectivity over hydrogen evolution.
• Salen-PIL(Zn) achieved 90.1% FECO at 90.1 mA cm-2, while Salen-PIL(Cu) yielded 54.5% FECH4 at 272.5 mA cm-2.

Conclusions:

• Atomically dispersed Salen-PIL(Zn/Cu) catalysts offer tunable selectivity for CO2 electroreduction.
• Catalyst design strategies involving ILs can enhance CO2 conversion efficiency and product selectivity.