Structure–Activity Relationship of the Polymerized Cobalt Phthalocyanines for Electrocatalytic Carbon Dioxide Reduction

Polymeric frameworks composed of molecular complexes have been attractive for the outstanding activity, selectivity, and stability toward CO 2 -to-CO conversion. In this work, polymerized cobalt phthalocyanines (CoPPc) with different functionalities were investigated with a series of spectroscopy characterizations, controlled-potential electrolysis, Tafel analysis, cyclic voltammetry analysis, and isotope labeling studies. The electronic structure of the Co center was revealed to be directly affected by the peripheral substituents via an inductive effect. Besides, the relationship between electronic structure and activity of the CoPPc-based catalysts for CO 2 electroreduction was successfully elucidated at the molecular level.