Salen ligand complexes as electrocatalysts for direct electrochemical reduction of gaseous carbon dioxide to value added products

Abstract

CO₂, being a linear and centrosymmetric molecule, is very stable, and the electrochemical reduction of CO₂ requires energy. Moreover, the CO₂ electroreduction proceeds at a significantly higher applied voltage than thermodynamically required. In this concern, salen ligand, H₂L^NO₂, and its corresponding Ni(II) and Cu(II) complexes are synthesized and reported for the first time as electrocatalysts for CO₂ electroreduction. Both the metal complexes are active for CO₂ reduction and surprisingly result in formation of C₁ and C₂ hydrocarbons. The complexes are found to be very efficient to minimize overpotential required for the reaction as compared to their pure metal counterparts. Thus, the present study opens up a new class of metal complexes for the efficient electrochemical reduction of CO₂ having the potential to generate hydrocarbons at lower overpotentials.