Conductive Phthalocyanine‐Based Covalent Organic Framework for Highly Efficient Electroreduction of Carbon Dioxide

Abstract The electroreduction of CO 2 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 CO 2 electroreduction reaction (CO 2 RR). 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 CO 2 RR. 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 CO 2 RR activity for 10 h. This work presents the implementation of the conductive COF nanosheets for CO 2 RR and provides a strategy to enhance energy conversion efficiency in electrocatalysis.