Enhanced Electrochemical Reduction of CO ₂ to CO upon Immobilization onto Carbon Nanotubes Using an Iron‐Porphyrin Dimer

Electrochemical reduction of carbon dioxide (CO 2 ) is a viable solution for conversion of atmospheric CO 2 to value‐added materials such as carbon monoxide (CO). In this project, a new urea iron‐tetraphenylporphyrin‐dimer (Fe‐TPP‐Dimer) was synthesized and applied for electrocatalytic CO 2 reduction under both homogeneous and heterogeneous conditions to selectively reduce CO 2 to CO. Immobilization of the catalyst onto carbon nanotubes (CNTs) in aqueous solution resulted in remarkable enhancement of its electrocatalytic abilities, with exceptional turnover frequencies (10 s −1 ), high faradic efficiency (FE) of ∼90%, and a current density of 16 mA/cm 2 at −0.88 V vs. RHE. This project exhibits the importance of molecular design in accessing heterogeneous applications with CNTs.