Electrochemically produced and regenerated cerium(IV) ions are a well-known redox mediator and used as a redox catalyst for the oxidation of alkyl aromatics. Detailed studies have been carried out on the design and the development of electrochemical cells for the electrochemical preparation of cerium(IV) methanesulphonate. In Ce(III)/Ce(IV) redox mediator system, cerium(IV) ion has been generated from cerium(III) in both divided and undivided electrochemical cell in high current efficiency and yield. (c) 2005 Elsevier B.V. All rights reserved.