Stable Dicationic Covalent Organic Frameworks Manifesting Notable Structure-Enhanced CO2 Capture and Conversion

Covalent organic frameworks (COFs) are a class of promising porous crystalline materials for both capturing and converting CO 2 into high-value-added products. However, long synthesis time and the need for cocatalyst restrict its potential for CO 2 conversion. Herein, bipyridine-based TAPT-BP-COF with high crystallinity as a skeleton is rapidly synthesized within only 1 h by the aid of supercritical CO 2 (scCO 2 ) activation. Then, the production of dicationic TAPT-BP 2+ -COF is accomplished by a quaternization reaction. The CO 2 capture capacity of TAPT-BP 2+ -COF improved by 55.6% due to its CO 2 -philic groups (imine and triazine groups), polar groups (−OH), charged skeleton, and suitable pore size, thus ensuring sufficient CO 2 around the catalytic active sites. Additionally, the outstanding structure-enhanced CO 2 conversion performance is observed due to the presence of the synergistic effect between –OH and Br – in the TAPT-BP 2+ -COF skeleton. The rate-determining step of cycloaddition is significantly accelerated without any solvents and cocatalysts compared to individual TAPT-BP-COF and [OH-BP] 2+ [Br] 2 – (BP 2+ moiety). Specifically, TAPT-BP 2+ -COF efficiently generates cyclic carbonate by heterogeneously catalyzing CO 2 -epoxide cycloaddition with the yield of 99.3% and has excellent stability that can be reused ten times without significant activity reduction. This work provides a novel perspective for the targeted design and rapid synthesis of charged dicationic COF-based catalysts for high efficiency and durability in CO 2 capture and conversion.