The effect of some non-corresponding ionic species on the
anodic process in the chlorate producing electrolytic cells has been
investigated. It was shown that increasing concentration of anions
such as chromate, nitrate and phosphate results in an increase in
the oxygen evolution rate. The effect exhibits an asymptotic
tendency at higher concentrations. The resemblance of the curve with
the adsorption isotherm suggests anion adsorption and its catalytic
effect on charge transfer as a possible cause of increasing electrochemical oxidation of available chlorine. The latter results in a
corresponding decrease of the current efficiency of chlorate production.
Hence, inspite of the benefitial effect of buffering by
some of the anions on the chemical conversion of available chlorine
into chlorate, the non-corresponding anion concentrations should
be kept as low as possible