Pore Geometry and Surface Engineering of Covalent Organic Frameworks for Anhydrous Proton Conduction.

Developing new materials for anhydrous proton conduction under high‐temperature conditions is significant and challenging. Herein, we create a series of highly crystalline covalent organic frameworks (COFs) via a pore engineering approach. We simultaneously engineer the pore geometry (generating concave dodecagonal nanopores) and pore surface (installing multiple functional groups such as −C=N−, −OH, −N=N− and −CF3) to improve the utilization efficiency and host–guest interaction of proton carriers, hence benefiting the enhancement of anhydrous proton conduction. Upon loading with H3PO4, COFs can realize a proton conductivity of 2.33×10−2 S cm−1 under anhydrous conditions, among the highest values of all COF materials. These materials demonstrate good stability and maintain high proton conductivity over a wide temperature range (80–160 °C). This work paves a new way for designing COFs for anhydrous proton conduction applications, which shows great potential as high‐temperature proton exchange membranes. [ABSTRACT FROM AUTHOR]