The Influence of Protonation on the Electroreduction of Bi (III) Ions in Chlorates (VII) Solutions of Different Water Activity

摘要

We examined the electroreduction of Bi (III) ions inchlorate (VII) solutions under varied protonation conditions ofthe depolariser using voltammetric and impedance methods.The results of the kinetic parameter correlation lead to thestatement that the changes in the amount of chloric (VII) acidagainst the amount of its sodium salt in the supporting electrolytesof the low water activity have a significant influenceon the rate of Bi (III) ion electroreduction. The increase of theconcentration of chloric acid sodium salt, aswell as the chloric(VII) acid alone within the particular concentration of thesupporting electrolyte, inhibits the process of Bi (III) ionelectroreduction. It should be associated with thereorganisation of the structure of the double layer connectedwith the slow dehydration inhibited by ClO 4− ions. The standardrate constants ks values with the increase of the chlorate(VII) concentrations for all the solutions examined of chlorates(VII) confirms the catalytic influence of the decrease ofwater activity on the process of Bi (III) ion electroreduction.The multistage process is confirmed by the non-rectilinear1nkf=f(E) dependences.