First steps toward the construction of a channel cell for electrochemical studies under hydrothermal conditions

Abstract

The high-T,p channel flow cell (HT-CFC) for electrochemical studies under hydrothermal conditions would allow to investigate at a fundamental level the interaction between new materials and media conditions such those found in modern power plants, industrial processes, and geochemistry. A first CFC prototype was constructed and the performance of the cell was studied using the oxidation of ferrocyanide in 0.1M KCl as reference system under room temperature conditions. A numerical simulation software, COMSOL Multiphysics, was used to analyze the experimental results. At the same time, the thermal stability of hydroquinone (H2Q) and 1,4-benzoquinone (BQ), a redox couple that it could be used to extend the evaluation of the CFC to higher temperatures and pressures was also investigated using UV-visible spectroscopy up to 250 ˚C at 70 bar. These studies confirmed H2Q is stable in hot compressed water (pH ~ 2) up to at least 250 ˚C at 70 bar, but BQ, the oxidation production of H2Q, decomposes at temperatures lower than 100 ˚C with the formation H2Q and other non-absorbing products.