Kityk A. Electrode processes in Cr(III)-methanesulfonic system

The subject of investigation: DEL and the electrode processes on the interface electrode/methanesulfonate solution. Metods of investigation: spectrophotometry and quantum-chemical calculations (to determine the characteristics of complex formation in the methanesulfonate solutions of trivalent chromium and the description of the geometric structure and electroactive methanesulfonate complex particles); photocolorimeters, potentiometers, titrimetry (for analysis of electrolytes and a description of their buffering capacity); the method of electrochemical impedance spectroscopy (to determine the true surface area of the solid electrodes, the potential of zero charge of the lead electrode); linear and cyclic voltammetry (to establish kinetics parameters of electroreduction of Cr(III) ions, to determine the activation energy of the discharge and diffusion, as well as the corresponding pre-exponential factors of the electrochemical reaction); chronoamperometry, volumetry and gravimetry (for partial dependence of cathode processes in the system Cr(III) - methanesulfonic acid). Theoretical and practical results: a complex of systematic experimental data about the features of the structure of the electric double layer (DEL) and the adsorption of aliphatic alcohols on the interface lead electrode/methanesulfonate solution at first described and shown that the methanesulfonate anions are characterized by low surface activity. Found that the electroreduction of Cr (III)> Cr (II) in the methanesulfonate Cr(III) salt solutions on Pb, Cd and Sn electrodes occurs irreversibly by the outer-sphere mechanism. It is shown that there are two forms of trivalent chromium methanesulfonate (violet and green) are distinguished by the standard rate constants of the discharge and diffusion coefficients. Proposed and tested method of processing the current-voltage relationships, which allows using the primary experimental data to determine the activation parameters of electroreduction and mass transfer. The novelty of the provisions and the results: the results about the structure of the electric double layer and adsorption of aliphatic alcohols on the interface lead electrode/methanesulfonate solution, a specific effect of the methanesulfonate anion on the structure aqueous solutions, kinetics of electroreduction of Cr(III) in methanesulfonate solutions are original and first obtained. Scope of use: results of the thesis can be applied to the study of adsorption phenomena and kinetics of electrode processes in methanesulfonate media and in teaching course "Physical Chemistry" and "Surface phenomena and disperse systems," when creating new efficient, resource-saving and environmentally friendly technologies with methanesulfonic acid.