Electroreduction of CO 2 (CO 2 RR) 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 CO 2 RR 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 CO 2 RR performance in water with 95% Faradaic efficiency of the CO 2 -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 CO 2 RR.

The electroreduction of CO2 to value‐added chemicals such as CO is a promising approach to realize carbon‐neutral energy cycle, but still remains big challenge including low current density. Covalent organic frameworks (COFs) with abundant accessible active single‐sites can offer a bridge between homogeneous and heterogeneous electrocatalysis, but the low electrical conductivity limits their application for CO2 electroreduction reaction (CO2RR). Here, a 2D conductive Ni‐phthalocyanine‐based COF, named NiPc‐COF, is synthesized by condensation of 2,3,9,10,16,17,23,24‐octa‐aminophthalocyaninato Ni(II) and tert‐butylpyrene‐tetraone for highly efficient CO2RR. Due to its highly intrinsic conductivity and accessible active sites, the robust conductive 2D NiPc‐COF nanosheets exhibit very high CO selectivity (>93%) in a wide range of the applied potentials of −0.6 to −1.1 V versus the reversible hydrogen electrode (RHE) and large partial current density of 35 mA cm−2 at −1.1 V versus RHE in aqueous solution that surpasses all the conventional COF electrocatalysts. The robust NiPc‐COF that is bridged by covalent pyrazine linkage can maintain its CO2RR activity for 10 h. This work presents the implementation of the conductive COF nanosheets for CO2RR and provides a strategy to enhance energy conversion efficiency in electrocatalysis.

The electrochemical conversion of CO2 into valuable chemicals would be an effective way to realize carbon-neutral energy cycle and alleviate energy crisis. Due to their porous crystalline structures and ordered...