Robust Amide-Linked Fluorinated Covalent Organic Framework for Long-Term Oxygen Reduction Reaction Electrocatalysis

Area of Science:

• Sustainable energy solutions
• Electrocatalysis
• Materials science

Background:

• Growing global energy demand necessitates sustainable and eco-friendly energy sources.
• The oxygen reduction reaction (ORR) offers a 2e^- pathway for green hydrogen peroxide (H₂O₂) production.
• Metal-free covalent organic frameworks (COFs) are promising electrocatalysts but often suffer from linkage instability.

Purpose of the Study:

• To enhance the chemical stability and electrochemical performance of COF electrocatalysts.
• To develop a robust metal-free electrocatalyst for efficient H₂O₂ production.
• To investigate the impact of post-synthetic linkage modification on COF properties.

Main Methods:

• Synthesis of an amide-linked COF via post-synthetic modification of an imine-linked COF.
• Electrochemical evaluation of the modified COF for oxygen reduction reaction (ORR).
• Analysis of H₂O₂ production selectivity and turnover frequency.

Main Results:

• The amide-linked COF exhibited enhanced chemical stability compared to the imine-linked precursor.
• The modified electrocatalyst achieved a high H₂O₂ selectivity of 98.5%.
• An improved turnover frequency of 0.155 s^-1 was recorded, competitive with state-of-the-art metal-free COFs.

Conclusions:

• Post-synthetic modification is an effective strategy to improve the stability and performance of COF electrocatalysts.
• The developed amide-linked COF is a highly selective and efficient electrocatalyst for H₂O₂ production.
• This work represents a significant advancement for metal-free, non-pyrolyzed electrocatalysts for sustainable energy applications.