Non-local effects in the kinetics of heterogeneous charge transfer reactions

The effect of the solvent spatial dispersion and the field penetration into a metal on the kinetic parameters of the heterogeneous charge-transfer rea ctions is studied. The calculations are based on the exactly solvable 'shar p boundary model' of the interface, the Born sphere model of an ion and the Lorentzian form for the dielectric function of the solvent. It is shown th at the reorganization Gibbs energy and the activation Gibbs energy decrease with decrease of the etectrode-reactant separation in accordance with Marc us theory tin which the non-local effects are neglected) and in contrast wi th the results of Dzhavakhidze, Kornyshev and Krishtalik [J. Electroanal. C hem. 228 (1987) 329]. The reorganization Gibbs energy is found to be smalle r than that given by the Marcus formula. The effect of the overscreening ph enomenon on the results obtained is discussed. (C) 2000 Elsevier Science S. A. All rights reserved.