Bockris and Potter

The concept of stoichiometric number was first introduced in electrochemistry by Horiuti and Ikusima [48, 49] for the hydrogen evolution reaction and discussed by Bockris and Potter [50, 52] and Parsons [47]. 

The stoichiometric number of a reaction is the number of times the rate-determining step occurs during one act of over-all reaction (65). Stoichiometric numbers are sometimes useful in determining mechanisms as long as one knows the probable paths for the reaction. Stoichiometric numbers were first used in electrode kinetic equations by Bockris and Potter (42) to obtain information on the mechanism of the hydrogen evolution reaction. 

In the past, there has been some dispute as to the zero potential at which rates on different metals should be compared. Most early discussions centered around the use of the p.z.c. of the metal (Antropov, Ref. 31 Grahame, Ref. 32 the latter calling the scale the rational potential scale ). Bockris and Potter decided that the rates of the electrocatalytic hydrogen evolution reaction should be compared at the zero-charge potentials of different metals, because of the log rate—O correlations reported in Ref. 7. This comparison is not only difficult to make, on account of the general problem of accurately determining the p.z.c. values in most cases, but, as shown above, is also not necessary. Indeed, it is clear that wide variations in... 

Bockris, J. O M. and Potter, E. C. (1952) The mechanism of hydrogen evolution at nickel cathodes in aqueous solutions. 

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