Étude des mécanismes de dissociation de l’eau dans les membranes échangeuses d’ions

Abstract

The electrochemical methods; linear sweep voltammetry and chronopotentiometry were carried out using Autolab PGSTAT30 instrument and the four electrodes cell. The evaluation of the iH+ shows that this contribution is (34%) for NH4+ and (7%) for K+. The power spectrum of electrical noise, obtained by the analysis of the chronopotentiometric results shows that the spectral density is more important for alkalis ions (Li+,Na+,K+) than for the ions NH4+ . The application of the theoretical model based on the transport equations NERNST-PLANCK to the systems electrode / MEI electrolyte / electrode and electrode/solid electrolyte / electrode are realized. The effect of parameters, membrane thickness, current density and the mode of transport, in the first system, and the presence of a significant gradient temperature located in the ionic electrolyte to high current densities are obtained.