VOLTAMMETRY IN GAS-PHASE ENVIRONMENTS

Cyclic voltammetric studies of solvent vapors were performed to invest igate the possibilities and limitations of electrochemistry in a gas p hase environment. No electrochemical response occurs unless the solven t adsorbs across the insulator between the electrodes. Ionic contact i s maintained by autoprololytic 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 reactio ns. The electrochemical signal in ion-generating solvents corresponds to faradaic processes; inert solvents generate simple capacitive respo nses. Electrolysis signals increase with autoprotolysis constant; a mi nimum dielectric constant of 5-10 is needed to allow electrolysis. Bas ed on the Frumkin correction, the electrolysis of solvent ions as well as solvent molecules may contribute to the current.