Regulating the Isomerization Geometry and Energy State of Covalent Organic Frameworks for Enhanced Oxygen Reduction Activity

Advanced Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 19, 2025

Abstract Embedding isomer entities onto crystalline frameworks with precisely defined spatial distributions represents a promising approach to enhancing the efficiency of oxygen reduction reaction (ORR) in fuel cells. However, accurately constructing covalent organic (COFs) regulate energy state effectively remains significant challenge. Herein, an innovative geometric isomerization strategy aimed at minimizing rotational barrier (ΔE), average local ionization (ALIE), and Gibbs free (ΔG) for ORR within COFs is proposed. Based on this strategy, isomeric Py‐COF‐αα 2,2‐substitution, Py‐COF‐ββ 3,3‐substitution, Py‐COF‐αβ 2,3‐substitution mainchain have been obtained. The electronic states intermediate adsorption capabilities are finely tuned through modification, yielding controllable chemical activity. Notably, lower ΔE between thiophenes achieves remarkable performance, evidenced by half‐wave potential 0.77 V vs reversible hydrogen electrode (RHE), surpassing most reported metal‐free electrocatalysts. Combined theoretical prediction situ Raman spectra, it revealed that increased dipole moment non‐uniform charge distribution caused endows pentacyclic‐carbon (thiophene β‐position) far from sulfur atoms efficient catalytic This work has opened up novel paradigm underscores pivotal role regulation facilitating catalysis.

Language: Английский

New Materials for Lithium–Sulfur Batteries: Challenges and Future Directions

Chemical Communications, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

The review highlights 3D graphene, MXenes, MOFs, and COFs as key materials that trap polysulfides, enhance conductivity, stabilize lithium metal for improved lithium–sulfur battery performance scalability.

Language: Английский