SUBSTANTIATION OF THE ELECTROLYTE COMPOSITION IN THE ELECTROCHEMICAL SYNTHESIS OF PEROXYLIC ACID

Abstract

lactic acid (PLA) is a strong disinfectant with a wide spectrum of antimicrobial activity. Its widespread use is hampered by the lack of an electrochemical technology for PLA synthesis, which will make it possible to develop local electrochemical generators for the production of disinfectants. There is no information about the standard potential of the СН3СH(OH)С(=О)ОН « СН3СH(OH)С(=О)ООН system, both in reference literature and professional scientific publications. It has been shown that the electrochemical synthesis of PLA will be combined with the processes of oxygen release and the formation of hydrogen peroxide. To inhibit side processes, an additive to a solution of lactic acid 0.5 mol dm-3 H2SO4 was used. The adsorption of sulfate ions leads to the displacement of a certain proportion of water molecules outside the boundaries between the phase boundaries. An almost 2-fold increase in the anodic current density was also noted at the potentials of electrochemical synthesis of peroxide compounds. It has-been found that a lactic acid molecule is integrated into the structure of the near-electrode layer with a carboxyl group directed towards the anode surface. The inflection of the current-voltage curve, at potentials more positive than 1.70...1.75 V, indicates the course of the combined processes of the formation of peroxide compounds, proceeding with a significant inhibition of the oxygen reaction at the Pt/PtO2 anode. The release of oxygen under these conditions occurs due to the formation and destruction of H2O2. The potential difference between the forward and reverse runs of the current-voltage curve indicates a significant effect of lactic acid on the adsorption processes on the anode surface. The results obtained confirmed the relevant the choice of the Pt/PtO2 anode for the electrochemical synthesis of PLA. The characteristics of the electrolyte for the electrochemical synthesis of PLA has been defined: 2 mol dm-3 of lactic acid, 0.5 mol dm-3 of sulfuric acid.