## current efficiency

Also contains definition of: metal distribution
https://doi.org/10.1351/goldbook.C01458
If several reactions take place simultaneously at the electrode a partial electrode @[email protected] (c.d.) $$j_{k}$$ can be assigned to each reaction. It is given by the @[email protected] of the reaction and by the @[email protected] of B reacting (per unit time and per unit electrode area) in the reaction considered. The current efficiency of reaction $$k$$, $$ɛ_{k}$$ is defined as the ratio of $$j_{k}$$ to the total c.d.: $ɛ_{k}=\frac{j_{k}}{\sum _{\begin{array}{c} m \end{array}}j_{m}}$ Note that $$ɛ_{k}$$ may be larger than one if cathodic and anodic reactions take place simultaneously at the same electrode. However, $$ɛ_{k}$$ still gives correctly the product yield, which is the quantity of industrial interest. The product yield is the @[email protected] of B produced per unit charge and is equal to $$\frac{ɛ_{k}\ \nu _{B,k}}{n_{k}\ F}$$ (in the absence of a @[email protected] which is consecutive to the @[email protected] and which consumes or produces species B). $$n_{k}$$ is the @[email protected] of @[email protected] $$k$$. Note that in the case of simultaneous electrode reactions the distribution of the partial c.d. $$j_{k}$$ may be different from that of the total c.d., i.e. the function $$\frac{\left(j_{k}\right)_{\text{x}}}{j}=f_{k}\left(x\right)$$ may be different from $$\frac{j_{\text{x}}}{j} = f(x)$$. In electroplating the term 'metal distribution' is sometimes used to designate the distribution $$f_{k}\left(x\right)$$ of the partial c.d. for metal deposition.
Source:
PAC, 1981, 53, 1827. (Nomenclature for transport phenomena in electrolytic systems) on page 1836 [Terms] [Paper]