Electrochemical Measurements by the External Pressure Balanced Reference Electrode System and the Evaluation of Thermal Diffusion Potential in High Temperature and High Pressure Aqueous Solutions

Abstract

The External Pressure Balanced Reference Electrode (EPBRE) system was applied to the electrochemical measurements in high temperature and high pressure aqueous solutions. Irreversible potentials arisen in the EPBRE system, such as liquid junction potential and thermal junction potentials were studied with comparison to the internal reference electrode system in 0.1 M KCl solutions at high temperatures. It was demonstrated that the potential measured by EPBRE system can be converted to the potentials referenced to standard hydrogen electrode potential at high temperature and also at 25ºC. The contribution of liquid junction potential and thermal diffusion potentials to the measured values was also evaluated in the EPBRE system.