A note on electrolysis with forced convection at large peclet number in a channel and an excess of supporting electrolyte

Abstract

Electrolysis of an aqueous solution of a metal salt with an excess of supporting electrolyte flowing in a two-dimensional channel is considered. The reaction kinetics is modeled by a Butler-Volmer law. The metal electrodes are symmetrically flush mounted in the channel walls, which are otherwise electrically insulating. Using the perturbation scheme originally proposed by Levich for electrolytes with an excess of supporting electrolyte, a solution in closed form, involving the root of a transcendental algebraic equation, is obtained for the polarization curve. For small and large values of the potential difference between the electrodes, explicit expressions for the polarization curve and the distributions of electric current and concentration on the electrodes are obtained. Particular attention is given to the conditions prevailing during the asymptotic approach to the limiting current.