Voltammetry in gas phase environments

Abstract

Cyclic voltammetric studies of solvent vapors were performed to investigate the possibilities and limitations of electrochemistry in a gas phase environment. No electrochemical response occurs unless the solvent adsorbs across the insulator between the electrodes. Ionic contact is maintained by autoprotolytic and acid-base reactions of the adsorbed solvent and trace impurities (e.g. water). In autoprotolytic solvents, ion concentration is not substantially enhanced by acid-base reactions. The electrochemical signal in ion-generating solvents corresponds to faradaic processes; inert solvents generate simple capacitive responses. Electrolysis signals increase with autoprotolysis constant; a minimum dielectric constant of 5-10 is needed to allow electrolysis. Based on the Frumkin correction, the electrolysis of solvent ions as well as solvent molecules may contribute to the current. © 1995.