Defect Engineering in Polymeric Cobalt Phthalocyanine Networks for Enhanced Electrochemical CO2 Reduction

Abstract The electrochemical reduction of CO 2 into fuels and valuable chemicals represents an appealing approach to alleviate energy crisis and global warming. Due to its sluggish reaction kinetics and the lack of suitable electrocatalysts it remains a major challenge. In this work, we report a facile synthetic approach to engineer a polymeric cobalt phthalocyanine network with rich defects for significantly enhanced electrocatalytic activity for CO 2 reduction. The successful defect engineering not only promotes the formation of a stronger binding surface towards CO 2 , but also simultaneously turns the electronic character of the resulting cobalt phthalocyanine framework. As a result, the new defective polymer exhibits highly selective catalysis of aqueous reduction of CO 2 into CO with a large faradaic efficiency of ca. 97 %, low applied overpotential of 490 mV (versus a reversible hydrogen electrode) and long‐term stability. We anticipated that this new strategy could inspire the discovery of new organic frameworks for efficient CO 2 reduction, such as those (defective MOFs, COFs etc.), evidently advancing the development of catalysts for the CO 2 reduction reaction.