Electrode kinetics of EU3+ in sodium perchlorate solutions in dimethylsulfoxide

The influence of the concentration of the sodium perchlorate supporting electrolyte on the standard electrode reaction rate constants for the one-electron reduction of Eu(CF3SO3)(3) on mercury in dimethylsulfoxide has been studied. The k(s)(app)-values were derived from both ac polarography on the dropping mercury electrode and from cyclic voltammetry on a hanging mercury drop in a two-electrode system. The ac data was evaluated by Randles [Trans. Faraday Soc. 48 (1952) 937] and by Sluyters [Rec. Trav. Chim. 79 (1960) 1092] methods. The standard reaction rates from cyclic voltammetry were extracted via a simulation program. Densities, viscosities. specific resistances (resistivities) and double layer capacitances of the electrolytes were measured. Correlations between electrolyte properties and the k(s)(app)-values were investigated. The standard electrode reaction rates were also treated within the Frumkin theory. (C) 2003 Elsevier B.V. All rights reserved.