Does the auxiliary electrode need to be isolated from the working electrode?
During any electrochemical experiment, a redox reaction occurs at the surface of the auxiliary electrode (to balance the redox reaction at the surface of the working electrode), and the products of this reaction can diffuse to the working electrode and interfere with the redox reaction occurring at that site. However, in electroanalytical experiments such as cyclic voltammetry, the time scale of the experiment is too short for this diffusion to be able to cause significant interference, so there is no need to place the auxiliary electrode in a separate compartment. However, electrosynthetic (bulk electrolysis) experiments are typically much longer than electroanalytical experiments, so separation of the auxiliary electrode is required (see, e.g., the BAS bulk electrolysis cell (MF-1056)).
During any electrochemical experiment, a redox reaction occurs at the surface of the auxiliary electrode (to balance the redox reaction at the surface of the working electrode), and the products of this reaction can diffuse to the working electrode and interfere with the redox reaction occurring at that site. However, in electroanalytical experiments such as cyclic voltammetry, the time scale of the experiment is too short for this diffusion to be able to cause significant interference, so there is no need to place the auxiliary electrode in a separate compartment. However, electrosynthetic (bulk electrolysis) experiments are typically much longer than electroanalytical experiments, so separation of the auxiliary electrode is required (see, e.g., the BASi bulk electrolysis cell (MF-1056)).
