Elucidating the reactivity and nature of active sites for tin phthalocyanine during CO2 reduction

Immobilized tin phthalocyanine dichloride (SnPcCl 2 ) was prepared by refluxing SnPcCl 2 and hydroxyl-functionalized carbon nanotubes in DMF with the addition of triethylamine, which exhibited minimal aggregation and approximately 2–3 folds improvement in activity towards CO 2 electroreduction compared to the physically mixed SnPcCl 2 /CNT hybrid. Cyclic voltammetry analysis and in situ UV-vis spectra revealed that metallic tin is the active site for CO 2 electroreduction, and the redox behavior of Sn 0 is affected by the adjacent demetallized macrocycles. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.