Design of stable covalent organic frameworks for transport regulation of mass and energy

This feature article discusses the design of stable covalent organic frameworks(COFs) for the transport regulation of protons,electrons, and radicals. Transporting these particles through materials is essential for many applications, and porous materials with high surface area and porosity have become powerful platforms for their development. However, the stability of the holes in the material is crucial for adjusting the transmission performance, which may change significantly when the material is not stable enough, and the structure changes when it is in service in the environment. Various strategies have been adopted to improve the stability of COFs, including introducing strong electron-donating groups into the COFs and introducing irreversible reactions into the COF synthesis process. The transport regulation in stable COFs has been explored, and the structure-function relationship has been established. The prospects and challenges of COFs for the transport regulation of protons, electrons, and radicals have also been discussed. Overall, the breakthroughs in COF field have opened new possibilities for developing advanced materials with improved transport properties. The stable COFs have potential applications in energy storage, catalysis,and sensing. However, further research is needed to understand the transport properties of COFs fully and to optimize their performance for specific applications.

In situ protonation in a locally flexible porous coordination polymer for enhancing proton-carrier loading and proton conductivity

Designing efficient proton-conductive materials is crucial in fuel cells.Yet,it remains a substantial challenge because of the issues in proton mobility,proton-carrier amount,and orientation of proton host materials.Herein,we report an in-situ protonation strategy to produce a locally flexible porous coordination polymer(PCP)to enhance the proton-carrier loading and proton conductivity.The local dipole flipping of the ligand allows effective proton exchange with low activation energy,promoting interpore proton transport through the pore apertures and pore walls.The protonation induces substantial charges to the frameworks and enhances the interaction with proton carriers,thereby increasing the loading of the proton carriers.By this design strategy,the resulting PCP exhibits enhanced phosphoric acid loading and extraordinary proton conductivities under both aqueous and anhydrous conditions compared to its isoreticular analog that features rigidity without proton-exchange capability.Our work provides a new avenue for designing proton-conductive materials that combine structural dynamics with performance merits.