Electrochemical and Corrosive Behavior of Iron in Acidic Chloride Media in the Presence of Pyrimidine

Abstract

The effect of pyrimidine concentration (0.0005…0.01 М) on the kinetics of the reaction of hydrogen evolution on iron in conventionally anhydrous ethylene glycol solutions with the electrolyte composition x M HCl + (1 – x) M LiCl (where x = 0.99; 0.5; 0.1; 0.05, Mmol/l). A quantitative assessment of the concentration of pyrimidine ions and the molecular form of pyrimidine depending on the acidity of the medium is given. As a result of electrochemical measurements, it was shown that the introduction of various concentrations of pyrimidine into conventionally anhydrous ethylene glycol solutions (with the ionic strength of the solution equal to one) changes the nature of the limiting stage. In the background conditionally anhydrous ethylene glycol solutions, the limiting stage is the discharge reaction, the kinetic parameters of which are in satisfactory agreement with Folmer’s theory. In the presence of pyrimidine in solutions in the concentration range under consideration, the delayed discharge stage changes to the delayed chemical recombination stage. The observed experimental results are primarily due to the acid-base interactions of pyridine and solvent molecules, which are primarily due to the structural features of the molecule of this additive and the ratio of the number of particles of the protonated form of pyrimidine to the number of particles of the molecular form in conventionally anhydrous ethylene glycol solutions.