MASS TRANSFER IN GAS-SPARGED POROUS ELECTRODES.

In cells that convert gaseous reactants that are only sparingly soluble in electrolyte solutions, mass transfer processes may control the reaction rate. Introduction of the two-phase mixture is expected to improve the mass transfer rates over those in single-phase flow by disturbing the solution close to the electrode, by bringing reactants close to the electrode surface (boundary layer penetration), and by continually resaturating the bulk solution. The purpose of this study was to evaluate the effect of the three mass transfer mechanisms of gas-liquid flow in porous electrodes by the use of the limiting current method.