The Kinetics of the Electroreduction Reaction of Molecular Oxygen in a Series of Quinoline Media

The quantitative investigations of the electroreduction of O-2 to O-2(-) at Au electrode in Q, IQ and a series of methylquinoline solvents were carried out using cyclic voltammetry (CV) and normal pulse voltammetry (NPV). The relevant kinetic parameters (i.e., the standard rate constant, k(o), and the cathodic transfer coefficient, alpha(c)) were evaluated by NPV. Results show that there is an inverse relationship of the formal potential (E-o,) to lowest unoccupied molecular orbital (LUMO) energy, indicating that O-2(-) is more stabilized in a solvent with lower LUMO; and a proportional relationship of k(o) to diffusion coefficient (D), indicating the solvent dynamics control of the electrode reactions. (C) 2017 The Electrochemical Society. All rights reserved.