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

The electrochemical reduction of CO2 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 CO2 reduction. The successful defect engineering not only promotes the formation of a stronger binding surface towards CO2, 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 CO2 into CO with a large faradaic efficiency of ca. 97%, low applied overpotential of 490mV (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 CO2 reduction, such as those (defective MOFs, COFs etc.), evidently advancing the development of catalysts for the CO2 reduction reaction.