Leonard, Matthew L., Latisha T. Johnson, Matthew C. Kittle, Michael A. Matthews, John W. Weidner. ELECTROCHEMICAL SUPEROXIDE GENERATION IN APROTIC SOLVENT UNDER O2 AND CO2 OVERPRESSURE
Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208 (matthews@eng.sc.edu)
The generation of superoxide ion (O2-), from the in-situ electrochemical reduction of oxygen, has been demonstrated in various aprotic solvent systems with supporting electrolyte; however such work has typically been limited to atmospheric pressure of oxygen. Here, we show superoxide generation via the reduction of molecular oxygen in a standard aprotic solvent under elevated pressures of oxygen, plus the generation of superoxide under additional carbon dioxide pressure. Supporting electrolyte tetraethylammonium perchlorate (TEAP, 0.1M) in acetonitrile solvent showed increased levels of current and solution conductivity as O2 and CO2 pressures were increased beyond atmospheric levels, indicative of an increase in superoxide generation. Such superoxide chemistry is one possible option being explored for the low-temperature oxidation of hazardous wastes, such as chlorinated biphenyls. Low-temperature electrochemical oxidation of wastes may provide a much-needed alternative to high temperature waste incinerators, whose use is greatly complicated by regulatory requirements and location of suitable sites. To perform the electrochemistry under elevated pressures, a high-pressure electrochemical cell was fashioned for the experiments.