Migrational chronoamperometry for various reaction stoichiometries and a variety of types of supporting electrolytes

The theoretical current-time relations are presented for chronoamperometry and the following experimental conditions: (1) the electrode process is of the type upsilon(S)S(ZS) double left right arrow upsilon(P)P(ZP) + ne(-), where one of the stoichiometric numbers (upsilon(S) or upsilon(P)) is an integer greater than or equal to 1; (2) the working electrodes are hemispherical microelectrodes; (3) a wide range of support ratios (the ratio of the bulk concentrations of supporting electrolyte and substrate) is employed; (4) various charges are assigned to the supporting ions. In some cases the influence of stoichiometry of the electrode reaction considered on the I-t dependences and the height of the steady-state current was significant. The influence of charges of supporting ions was clearly seen on the chronoamperometric curves for the most resistive system, i.e., uncharged substrate and small support ratio. Since the time interval used in this paper was appropriately large to reach steady-state, the theoretical results obtained are also an extension to those given by Myland and Oldham [J. Electroanal. Chem., 347 (1993) 49]. (C) 1997 Elsevier Science S.A.