| Affiliation: | 1. Department of Chemistry, Inorganic Chemistry IV, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany;2. Department of Chemistry, Inorganic Chemistry IV, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany Present adress, Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT, Institute Branch Sulzbach-Rosenberg, Department Renewable Energy, An der Maxhütte 1, 92237 Sulzbach-Rosenberg, Germany |
| Abstract: | Electrochemistry and its analytics are essential in a variety of scientific and technological fields where properties related to reduction-oxidation reactions, so-called redox properties, are to be explored. While methodological standards for experiments are well established at room temperature, this is still untrue at sub-zero/cryogenic temperatures, the conditions required for the survey of (ultra−)rapid processes and their intermediates. Problems due to “hand-waving” temperature regulation/conditioning and common usage of pseudo-reference electrodes renders cryo-electrochemistry a great challenge. Herein, we describe a robust setup for performing reliable cryo-electrochemical experiments down to −80 °C. It combines highly stable but flexible temperature conditioning with gas-tight sealing of the electrochemical cell setup. Modification of a commercial palladium hydride reference electrode (PdH RE) allows for rapid temperature cycling under cryogenic conditions in aprotic organic solvents. Validation of the setup with the well-known Ferrocene|Ferrocenium (Fc|Fc+) redox couple gave good compliance with literature data at room temperature in a range of organic solvent-based electrolytes. Evaluation of temperature-dependent diffusion kinetic parameters, such as diffusion coefficients (D) and diffusional activation energies (Ea,D) from CVs at multiple potential scan-rates and temperature levels emphasize the reliability of the presented cryo-electrochemical setup. |
