Gas-Generating Porous Electrodes: Calculating Characteristics in the Low-Polarizability Portion

Abstract

It is shown in the paper how specific features of the structure of the porous space in gas-generating porous electrodes (GGPE) create conditions for the emergence of a low-polarizability portion (LPP) in a polarization curve (PC). A set of equations is derived, which allows one to perform calculation of PC in the initial part of LPP. In the region of small overvoltages and in the initial part of a low-polarizability portion, calculations of basic characteristics of GGPE are performed. The calculations are carried out with the values of constants that are close to those that take place for the process of chlorine generation in dimensionally stable anodes. The shape of PC is established, together with the distribution of the oversaturation of electrolyte solution with gas over the GGPE thickness, the specific liquid surface area at which the electrochemical process of gas generation occurs, the amount of gas in the pores of the porous electrode, the overvoltage dependence of the oversaturation of electrolyte solution with gas at the front surface of GGPE, and the magnitude of the effective penetration depth of the process of gas formation into the porous electrode.