Carbonyl-linked cobalt polyphthalocyanines as high-selectivity catalyst for electrochemical CO₂ reduction

One type of carbonyl-linked cobalt polyphthalocyanine (CL-CoPPc) is synthesised as catalysts for use in electrochemical carbon dioxide (CO2) reduction (ECR). Carbonyl linkages can decrease the intermolecular pi-pi stacking, and serve as intramolecular "gullies" to impede proton transfer and the hydrogen evolution reaction (HER). Therefore, the CL-CoPPc exhibits highly active and selective CO2 reduction to carbon monoxide (CO).