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The limiting current for reduction of ferricyanide ion at nickel: The importance of experimental conditions
Author(s) -
Szánto D. A.,
Cleghorn S.,
PoncedeLeón C.,
Walsh F. C.
Publication year - 2008
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.11420
Subject(s) - limiting current , laminar flow , chemistry , electrolyte , ferricyanide , current (fluid) , rotating disk electrode , analytical chemistry (journal) , nickel , voltammetry , aqueous solution , electrode , limiting , thermodynamics , ion , electrochemistry , cyclic voltammetry , inorganic chemistry , chromatography , physics , mechanical engineering , organic chemistry , engineering
Steady state, hydrodynamic voltammetry is a well‐established technique to measure the rate of mass transport of an electroactive species to, or from, a solid surface electrode in an aqueous electrolyte. Limiting current measurements during the reduction of ferricyanide (hexacyanoferrate III ) ion at a nickel rotating disc electrode (RDE) are critically considered, and the accuracy of the technique is quantitatively assessed. The importance of surface pretreatment, type of indifferent electrolyte, and the effect of sunlight are considered. Limiting current values can show large deviations from the values predicted by the Levich equation for laminar flow to a polished RDE when unsuitable conditions are employed, despite the appearance of well‐defined limiting current plateaux. Using appropriate pretreatment and experimental procedures, the averaged mass transport coefficients or limiting currents values can be obtained, which are close to the values predicted by the Levich equation for laminar flow to a hydrodynamic smooth RDE. © 2008 American Institute of Chemical Engineers AIChE J, 2008