• Olesia B. Shmychkova Ukrainian State University of Chemical Technology, Dnipro, Ukraine, Ukraine
  • Dmitry V. Girenko Ukrainian Stste University of Chemical Technology, Ukraine
  • Alexander B. Velichenko Ukrainian State University of Chemical Technology, Ukraine



hypochlorous acid; electrolysis; chlorine evolution reaction; oxygen evolution reaction.


In the review article, a critical analysis of the literature was carried out, which showed the almost complete absence of systematic studies of electrochemical processes implemented at anodes in low-concentration sodium chloride solutions. The vast majority of works are devoted to the study of the regularities of chlorine evolution reaction in highly concentrated NaCl solutions on the surface of oxide catalysts, which often contain oxides of ruthenium and iridium. Taking into account the variety of works, today there is no universal mechanism that describes the reaction of chlorine evolution under various conditions and on the surfaces of electrocatalysts of various nature.  Comprehensive data on the peculiarities of such processes in low concentrated chloride solutions are presented. It is shown that the regularities of such processes are due to the participation of oxygen-containing particles with different bond strengths in individual steps. It was found that the electrocatalytic activity of electrodes in anodic processes in low concentration chloride solutions was due to the strength of the bond of chemisorbed oxygen-containing particles of different nature with the anode surface. Participation in the oxidation of Cllabile oxygen-containing particles of a certain energy increases the rate of formation of hypochlorous acid and leads to inhibition of undesirable reactions of oxygen evolution and synthesis of chlorates and chlorites. It is shown that the modification of the anode surface with palladium makes it possible to significantly increase their selectivity for the synthesis of hypochlorous acid from low concentration chloride solutions.


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