Successive Electrode Reactions with One Rate-Determining Step

This case is similar to ease d. The coverage is a function of rj  

Summarizing the preceding considerations it may be said that /o,v is accessible to an experimental determination in cases b, d, f, h and Iq j in case c for weak interaction between H atoms and electrode. For strong interaction, /q, v can be determined in case b and /q,h in case g. It is assumed that rj does not approach values for which one of the two discharge reactions becomes barrierless. 

Successive Electrode Reactions with One Rate-Determining Step 

An electrochemical reaction may be a sequence of several steps involving one or more intermediates. If a particular step is rate-determining, the standard free energies AGf and AG2 can be computed. The method that is commonly employed is to assume quasi-equilibrium for all the preceding steps and thus to obtain the concentration of the intermediates as a function of potential (compare cases c and f in section 2 of this chapter). In an alternate derivation Parsons [17] treated the passage of the representative point of a system over a series of activation barriers. The state P immediately before the highest barrier and the state Q immediately after it have to be considered besides the initial and final states. This treatment [17-19] which is equivalent [18] to the quasiequilibrium analysis is discussed subsequently. 

Kinetics of Electrode Reactions on Homogeneous Surfaces and Influence 

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