The EE-Comproportionation Mechanism

Two-electron transfers (EE) in which the second electron transfer is less favourable than the first are very commonly encountered in voltammetry. If we denote the species involved as A, B and C, respectively, then the comproportionation reaction is favourable  

If the reaction is reversible, the Nernst equation relates the concentrations of A, B and C at the electrode surface, and these are also related by conservation of mass. Hence at a = 0  

In bulk u = 2 c at X = 0 it follows from substitution that the Nernstian relationships that cg and cc can be expressed as functions of ca, and so since a = c  

Therefore u is completely described by equations which do not contain kcomp or fcdisp. and since the current is given  

if the presence of B can be determined by an analytical technique, or if it can be determined whether the mass transport of A or B to the electrode is rate-limiting, it is possible to determine whether or not the comproportionation process is active. 

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