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.