6 - Charge Transfer

Abstract

The stoichiometric number of the electron is one that is usually assumed for the elementary charge transfer step. Reduced and oxidized components have different solvation numbers. The general kinetic equations will be developed for this reaction. One description of the electron transfer was developed by Gerischer, based on the former work of Gurney and Essin. Another description goes back to the work of Marcus. Other contributions during the development of the basic theory came from Dogonadze, Levich, Chizmadzhev, Kuznetsov, and others. The transfer of an electron into the metal can occur if the electron on an energy level, Ee , in the electrolyte finds an unoccupied energy level at the same energy, Ee, in the metal. The intensity of the electron transfer is proportional to the density of occupied electron-energy levels in the electrolyte (the density of reduced ions, Dred) times the density of unoccupied energy levels in the metal, Nun. Otherwise, the transfer of an electron from the metal into the electrolyte can occur if the electron on an energy level, Ee, in the metal finds an unoccupied energy level at the same energy, Ee, in the electrolyte. The intensity of electron transfer is proportional to the density of unoccupied electron-energy levels in the metal, Nun, times the density of unoccupied energy levels in the electrolyte.