If several reactions take place simultaneously at the electrode a partial electrode current density
can be assigned to each reaction. It is given by the stoichiometry
of the reaction and by the amount of substance
reacting (per unit time and per unit electrode area) in the reaction considered. The current efficiency of reaction
is defined as the ratio of
to the total c.d.:
may be larger than one if cathodic and anodic reactions take place simultaneously at the same electrode. However,
still gives correctly the product yield, which is the quantity of industrial interest. The product yield is the amount of substance
produced per unit charge and is equal to
(in the absence of a chemical reaction
which is consecutive to the electrode reaction
and which consumes or produces species B).
is the charge number
of electrode reaction
. Note that in the case of simultaneous electrode reactions the distribution of the partial c.d.
may be different from that of the total c.d., i.e. the function
may be different from
In electroplating the term 'metal distribution
' is sometimes used to designate the distribution
of the partial c.d. for metal deposition.
PAC, 1981, 53, 1827
(Nomenclature for transport phenomena in electrolytic systems)
on page 1836