Voltammetric Measurement in Supercritical CO_2 Utilizing a Water-in-CO_2 Microemulsion

摘要

A novel method for voltammetric measurement in supercritical CO_2 is described. In this method a water-in-supercritical CO_2 microemulsion is utilized to raise the conductivity of the fluid phase. Well-defined voltammograms for the redox reactions of ferrocene and tetramethyl-p-phenylenediamine were obtained in supercritical CO_2 in the presence of the microemulsion. The electrolysis product is stabilized in the water core of the microemulsion. This implies a wide range of electrochemical synthesis involving ionic or radical species in supercritical CO_2 may be possible utilizing the microemulsion. The electrochemical results obtained from the water-in-supercritical CO_2 microemulsion system are different from that obtianed from a supercritical CO_2-ethanol mixture system.