Étude de la reduction électrochimique de AlCl3 dans le dimethylsulfoxyde à 25°C

The electrochemical reduction of AlCl₃ in dimethylsulphoxide at 25°C was studied by triangular voltammetry on platinum electrodes. The reduction mechanism corresponds to the kinetic scheme: $$Ox(ads) + ne to Red$$ where Ox is irreversibly adsorbed on the cathode. The reduction peak of the aluminium ions, Al(III), appears at ?1.96±0.05 V versus the reference electrode which is the half cell Ag/AgCl ₂ ^? 10^?3 M, LiCl 0.1 M. It is preceded by another badly defined peak around ?1.74 V, very probably due to the reduction of the protons present in traces in the electrolyte solution. The value of the quantityan _a (wherea is the transfer coefficient andn _a is the number of electrons involved in the rate determining step) was determined as 0.45±0.05 from measurements of all the experimental curves.