Electrochemical experiments such as cyclic voltammetry and the potentiostatic relaxation techniques, chronoamperometry and chronocoulometry, can be performed in cryogenic environments (>—130 °C). Low-temperature electrochemical cells have been designed to perform these experiments with reasonable facility. A variety of solvent/supporting electrolyte systems have been evaluated for low-temperature use and butyronitrile/0.1M TBAP appears to be the best “all-purpose” low-temperature medium. Although the use of a low-temperature environment in electrochemistry results in some time response degradation, the electrical double layer can still be charged in less than 0.001 sec under all conditions tested. Double potential step chronoamperometry and chronocoulometry have the special advantage for low-temperature work that their characteristic ratio responses, ia/ic and Qb/Qf, respectively, are temperature independent in the absence of coupled chemical reactions. Similar temperature independent ratios are formulated for other two-step electrochemical techniques.
ASJC Scopus subject areas
- Analytical Chemistry