Comparing electrocatalytic and chemical oxygen reduction reactions by a molecular copper complex

Abstract

Inspired by the Cu_B site in cytochrome c oxidase, a molecular Cu^II complex (1) featuring a mixed pyridine-phenol ligand has been designed and synthesized. Studies of both electrocatalytic and chemical oxygen reduction reactions in the presence of 1 demonstrate a 4e^–/4H⁺ reduction of O₂. Kinetic analysis reveals distinct reaction mechanisms for the chemical and electrocatalytic pathways, and the study highlights the crucial role of the ligand backbone in the ORR process.