EFFECT OF MULTIPLE REACTIONS ON METAL-DEPOSITION IN FLOW-THROUGH POROUS-ELECTRODES

Two different reaction systems were investigated in a flow-through porous electrode: (i) FeSO4, Fe2(SO4)3, and CuSO4 in H2SO4, and (ii) CuSO4 and CoSO4 in K2SO4. The porous cathode was fabricated from Pt screens through which convection of electrolyte occurred parallel to the flow of electrical current in the solution phase. The local rate of each cathodic reaction was measured and compared to theoretical predictions. The mathematical model incorporated the effects of internal mass transport, ohmic resistance in the electrolyte, and multiple electrochemical reaction kinetics under conditions of steady plug flow of electrolyte. The use of literature values for system parameters yielded predictions of current distributions which agreed favorably with the experimental data over the range of flow rates, applied potentials, and reactor lengths investigated. Depending upon operating conditions, the calculated collection efficiencies agreed to within 0-9% of the corresponding experimental values. © 1979, The Electrochemical Society, Inc. All rights reserved.