Electrochemical reactions with protonations at equilibrium Part XVI. The 1e −,2H + ladder scheme followed by irreversible dimerizations

Abstract

The 1e −,2H + electrochemical reaction (six-member ladder scheme) is studied when the protonations are at equilibrium, and when the reaction products undergo irreversible dimerizations. The results are valid for a surface reaction (adsorbed species, Langmuir isotherm), or for a heterogeneous reaction. If the symmetry factors of the elementary electrochemical reactions are equal to 0.5, the system behaves as a simple monoelectronic process, with an apparent rate constant k eapp, followed by a dimerization with an apparent constant k app. The expressions of the variations of k app with pH are established; they allow discrimination between the diverse types of dimerizations.