Influence of Mass Transport on Charge Transfer. Electrochemically Reversible and Irreversible Processes

3 Influence of Mass Transport on Charge Transfer. Electrochemically Reversible and Irreversible Processes 

In Sections 4.1 and 4.2, the electron transfer and the mass transport involved in a simple electrode reaction [simple = not complicated by preceding or following reactions, by absorption, or by formation of phases (see Section 2.2)] have been treated separately. However, it is to be expected that in reality both phenomena act in a concerted manner during a faradaic process. Thus, as seen previously, even the simple electrode process  

OXftmik of solution) (electrode surface) MASS TRANSPORT O felectrode surface) t riQ, - - (electrode surface) ELECTRON TRANSFER 

In this connection, there are two fundamental types of behaviour  

It must, however, be taken into account that the concept of electrochemical reversibility or irreversibility of an electron transfer is relative. In fact, to accelerate the redox processes one can act either on the mass transport (by stirring the solution) or on kRed and k0x (by changing the electrode potential, as seen in Section 4.1.1). 

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