The influence of acetazolamide (ACT) on the kinetics and the mechanism of electroreduction of In(III) ions as a function of changes of the water activity was investigated using electrochemical methods (DC, SWV, CV and EIS, CV). The multi‐step mechanism of the electroreduction process should take into account the dehydration step of indium ions and the presence
of In ‐ ACT (,,cap‐pair” effect) active complexes, mediating electron transfer, located in the adsorption layer.
Differences in the electrode mechanism in the presence of ACT were observed for higher chlorates(VII) concentrations
(above 4 mol‧dm‐3 chlorates(VII)) reflected by a lack of step wise nature of the electrode process. The highest catalytic activity was observed in 4 mol·dm‐3 chlorates(VII).