Electroreduction of the bromate anion on a microlectrode in excess acid: solution of the inverse kinetic problem

Acidic aqueous solutions of bromic acid salts (bromates) are promising electrolytes for redox flow batteries due to their record high power capacity and the rate of electrode reactions proceeding in the autocatalytic regime. The paper gives a comparison of the results of mathematical modeling and experimental measurements of steady state currents of bromate anion electroreduction in sulfuric acid medium on microelectrodes of various radii. An algorithm of solving the inverse problem suitable for determination of the key transport and kinetic process parameters was proposed and tested.

Adsorption of Bromic Acid Ion in Water by the Reduced Titanium Oxide

Because bromic acid ion generated by the ozone processing of drinking water for sterilization is strong carcinogenic, there is a high possibility in persons health hazard. The titanium dioxide was reduced at 900-degree Centigrade by the gas atmosphere (CO or H2). It was found that the concentration of the bromic acid ion in water was decreased at time when the reduced titanium oxide was added to water including the bromic acid ion. The bromic acid ion in water could be adsorbed by the titanium oxide reduced. In addition, it was suggested that the bromic acid ion could be decomposed into the bromide ion with low carcinogenic by using the photocatalitic function of titanium oxide under UV irradiation.

Utilisation de l'ortho-tolidine pour l'étude des réactions des halogénates et halogénites

We have shown previously that ortho-tolidine greatly simplifies the kinetic study of redox reactions of chlorite by reacting with intermediate products and eliminating side reactions. The present study shows the validity of the method in the case of bromate reactions. For the bromate–bromide reaction it gives the classical fourth-order rate law with k = 1.54 M−3 s−1 in perchloric acid solutions at 25 °C and 1 M ionic strength, and an acidity constant of bromic acid of 2.9. This method is then used to study the reaction between bromate and chlorite, a complex reaction in the absence of ortho-tolidine. The rate law is[Formula: see text]with k = 0.83 + 0.76 [H+] in the same conditions. If [H+] = 0.1 M the apparent activation energy is 47.4 kJ/mol.