Post-synthetic modification of covalent organic frameworks for CO₂ electroreduction

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Covalent organic frameworks (COFs) are explored as catalysts for CO2 reduction.
• Amine-linkages and ionic frameworks in COFs can enhance CO2 binding and electronic conductivity.
• Direct synthesis of COFs with both amine-linkages and ionic frameworks is challenging due to electrostatic repulsion.

Purpose of the Study:

• To develop high-efficiency COF catalysts for CO2 reduction reaction.
• To establish structure-performance correlations in COFs for CO2 reduction.
• To overcome synthesis challenges for dual-functional COFs.

Main Methods:

• Modulating linkers and linkages of template COFs.
• Synthesizing dual-functional COFs through double modifications.
• Evaluating catalytic performance via CO2 reduction reaction assays.
• Utilizing theoretical calculations to understand reaction mechanisms.

Main Results:

• Dual-functional COFs exhibit tuned CO2 binding ability and electronic states.
• Achieved high selectivity with a maximum CO Faradaic efficiency of 97.32%.
• Obtained high turnover frequencies of 9922.68 h⁻¹.
• Theoretical calculations indicate easier formation of intermediate *CO from COOH*.

Conclusions:

• The developed dual-functional COFs significantly outperform base and single-modified COFs.
• Structural modifications in COFs enable controllable activity and selectivity for CO2 reduction.
• This study provides valuable insights for designing advanced COFs for CO2 electroreduction.