A theory for electron transfer across the electrode/electrolyte interface involving more than one redox ion

A theory for electron transfer between a metal electrode and several redox species in a polar electrolyte is developed within the context of the Anderson-Newns Hamiltonian. Analytical expressions for the adiabatic ground state solvent free energy surfaces are derived, and it is shown how these expressions can be evaluated self-consistently. The shape of the adiabatic potential surfaces, and thus the thermodynamic and equilibrium rate characteristics of the electron transfer process, are shown to strongly depend on several key parameters. The effect of an external electric field on the free energy surface is also analyzed. (C) 1997 American Institute of Physics.