Integration of Strong Electron Transporter Tetrathiafulvalene into Metalloporphyrin-Based Covalent Organic Framework for Highly Efficient Electroreduction of CO₂

Electroreduction of CO₂ (CO₂RR) into value-added fuels is of significant importance but remains a big challenge because of poor selectivity, low current density, and large overpotential. Crystalline porous covalent organic frameworks (COFs) are promising alternative electrode materials for CO₂RR owing to their tunable and accessible single active sites. However, the poor electron-transfer capability of COFs limits their application. Herein, a tetrathiafulvalene (TTF) strut was integrated into a two-dimensional cobalt porphyrin-based COF (TTF-Por­(Co)-COF) to enhance its electron-transfer capability from the TTF to the porphyrin ring. Compared with COF-366-Co without TTF, TTF-Por­(Co)-COF showed enhanced CO₂RR performance in water with 95% Faradaic efficiency of the CO₂-to-CO conversion at −0.7 V vs RHE and a partial current density of 6.88 mA cm^–2 at −0.9 V vs RHE. This work provides a new insight for the rational design of porous organic framework materials for improving the activity of CO₂RR.