New Electrochemical Channel Flow Cell Design for Electrochemical Studies at Elevated Temperatures and Pressures

Abstract

Temperature exerts a considerable influence on the efficiency of chemical and electrochemical processes, and it is expected that studies under wide temperature and pressure (T and p) conditions can significantly impact fields of technological interest such as energy storage and conversion, water treatment, waste conversion, metal recovery, and electrosynthesis, among others.1 The electrochemical studies conducted by Bard’s group in near-critical and supercritical aqueous solutions,2 as well as the contributions made by MacDonald’s and Lvov’s3,4 groups on corrosion and pH determination in hydrothermal systems, offer valuable insights into the effects of temperature and pressure on electrochemical reactions under extreme conditions and construction materials and electrode designs. Other studies in the field, though they did not reach such harsh conditions, made valuable contributions by proposing innovative hydrodynamic electrode systems, from channel cells for studies up to 110 oC,5 a rotating disc electrode for temperatures up to 150 oC,6 and even an imping jet electrode able to reach 210 oC.7 Unfortunately, these studies were rarely expanded to more than one or two systems.In this work, various hydrodynamic electrode configurations have been examined to conclude that the channel flow cell design presents several advantages over other systems for high T and P applications. These cells can provide consistent and reproducible mass transport conditions across a broad range of flow rates and allow channel dimension adjustments to tackle diverse technological challenges. Furthermore, this configuration aligns well with spectroscopic techniques like Raman/SERS (surface-enhanced Raman spectroscopy). COMSOL Multiphysics was used when designing the cell prototype, and validation of the model was carried out using data from previous studies.8 The high T,p cell uses disposable thin-film electrodes (TFEs) patterned onto sapphire wafers through nanofabrication methods; a significant amount of time has been invested in testing the performance of the TFEs up to at least 150°C. These results will also be presented along with experiments conducted with the new channel cell under ambient conditions. References (1) Giovanelli, D.; Lawrence, N. S.; Compton, R. G., Electroanalysis (New York, N.Y.) 2004, 16 (10), 789-810.(2) Liu, C.-y.; Snyder, S. R.; Bard, A. J. J. Phys. Chem.B 1997, 101 (7), 1180-1185.(3) Macdonald, D. D. Corrosion 2013, 34 (3), 75-84.(4) Balashov, V. N.; Fedkin, M. V.; Lvov, S. N., J. Electrochem. Soc. 2009, 156 (7), C209.(5) Wang, H.; Jusys, Z.; Behm, R. J.; Abruña, H. D., J. Electroanal. Chem. 2021, 896, 115251.(6) Fleige, M. J.; Wiberg, G. K.; Arenz, M., Rev Sci Instrum 2015, 86 (6), 064101.(7) Trevani, L. N.; Calvo, E.; Corti, H. R., Electrochem. Commun 2000, 2 (5), 312-316.(8) Moorcroft, M. J.; Lawrence, N. S.; Coles, B. A.; Compton, R. G.; Trevani, L. J. Electroanal. Chem. 2001, 506 (1), 28-33.