KINETICS OF ELECTROREDUCTION OF ZN2+ AT MERCURY IN NONAQUEOUS SOLUTIONS

The electroreduction of Zn2+ was studied in propylene carbonate (PC), acetonitrile (ACN), and hexamethylphosphoramide (HMPA) on mercury at v arious concentrations of tetraethylammonium perchlorate as a supportin g electrolyte using de polarography, cyclic voltammetry, chronoamperom etry, and ac polarography. It was found that in PC and ACN the electro reduction process proceeds in one step. In HMPA, however, the electror eduction proceeds through a CEE mechanism in which a chemical reaction is followed by a charge transfer in two steps. The heterogeneous rate constants, corrected for the double layer effects, decrease with incr ease in the solvent donor number. The elecuoreduction process proceeds through the cation transfer mechanism.