TABLE OF CONTENTS The composition of a good reference electrode (RE) must remain effectively constant, unvarying for the duration of an experiment, in order to provide a stable potential for controlled regulation of the working electrode (WE) potential. The chosen RE should be an ideal nonpolarizable electrode (1), i.e., its potential does not change regardless of current flow through the RE. The reaction at the RE should be reversible, permitting a potential to be calculated from the Nernst equation, as well as have the capability to recover its potential after a current stress. This requires that the RE act as a source or a sink for small currents due to imperfections in potentiostat or galvanostat design without displaying a change in its potential throughout the duration of the experiment.
Many considerations must be weighed in choosing a suitable RE for an experiment. Proper experimental design must prevent incompatible species present in the electrolyte from reacting with the RE materials. For instance, an ionic species with poor solubility can precipitate in the frit, clogging the RE, and thus increasing the junction potential. Additionally, species that are in the electrochemical cell can interfere with the performance of an RE by poisoning the controlling redox process (i.e., H 2 catalysis), or increase the solubility of the reference couple (i.e., AgAgCl). Cell conditions such as pressure and temperature must...
