The electrocatalytic conversion of CO 2 into valueadded chemicals is apromising approach to realize ac arbonenergy balance.H owever,l ow current density still limits the application of the CO 2 electroreduction reaction (CO 2 RR). Metal-organic frameworks (MOFs) are one class of promising alternatives for the CO 2 RR due to their periodically arranged isolated metal active sites.H owever,t he poor conductivity of traditional MOFs usually results in al ow current density in CO 2 RR. We have prepared conductive two-dimensional (2D) phthalocyanine-based MOF (NiPc-NiO 4 )n anosheets linked by nickel-catecholate,w hichc an be employed as highly efficient electrocatalysts for the CO 2 RR to CO.T he obtained NiPc-NiO 4 has ag ood conductivity and exhibited av ery high selectivity of 98.4 %t oward CO production and al arge CO partial current density of 34.5 mA cm À2 ,o utperforming the reported MOF catalysts.T his work highlights the potential of conductive crystalline frameworks in electrocatalysis.

Herein, an effective tandem catalysis strategy is developed to improve the selectivity of the CO 2 RR towards C 2 H 4 by multiple distinct catalytic sites in local vicinity.A n earth-abundant elements-based tandem electrocatalyst PTF-(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel-nitrogen sites (PTF(Ni)) for the enhanced CO 2 RR to produce C 2 H 4 .T he Faradaic efficiency of C 2 H 4 reaches 57.3 %a tÀ1.1 Vv ersus the reversible hydrogen electrode (RHE), whichi sa bout 6t imes higher than the non-tandem catalyst PTF/Cu, whichproduces CH 4 as the major carbon product. The operando infrared spectroscopya nd theoretic density functional theory (DFT) calculations reveal that the local high concentration of CO generated by PTF(Ni)s ites can facilitate the CÀCc oupling to form C 2 H 4 on the nearby Cu NP sites.T he work offers an effective avenue to design electrocatalysts for the highly selective CO 2 RR to produce multicarbon products via atandem route.

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.