Effect of Alkali Concentration on the Rates of the Target and Side Cathode Reactions Involved in the Electrolysis of Tellurite Solutions
A. G. BELOBABA, A. I. MASLIY
Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: теллур, дителлурид-анион, щелочные теллуритные растворы, электролиз, скорость реакций, предельный ток, tellurium, ditelluride anion, alkaline tellurite solutions, electrolysis, reaction rate, limiting current
Pages: 360-365
Abstract
The effect of KOH concentration on the rate of the target reaction of metal tellurium deposition from alkaline tellurite solutions and on the rate of the side reaction of tellurium dissolution was studied by means of voltammetry with the linear potential scanning on a graphite electrode coated with tellurium deposit. It was established that KOH only weakly (with a change by 5-10 %) affects the rates of the target and side reactions within the range of alkali concentrations 2-4 M, which is used for the production of tellurium. The reasons of a decrease in the rates of the target and side reactions at low alkali concentrations were considered. It was shown that the target and side cathode reactions have the diffusion-determined nature in the range of alkali concentrations 0.5-4 M with tellurium deposition and 0.1-4 M with tellurium dissolution. The side cathode reaction of Те dissolution has a one-electron mechanism, and it requires 20 % of the amount of electricity used for tellurium deposition.
DOI: 10.15372/CSD2020241
|
