Study of the Influence of Electrode Material and Electrolyte Composition on Cathode and Anodic Overvoltage during Electrolysis

The aim of the research was to study the effect of the electrode material and the electrolyte composition on cathode and anodic overvoltages during electrolysis. The relevance of the present work is due to the widespread use of electrolysis in the production of hydrogen, chlorine, and alkalis and other areas where overvoltages caused by kinetic constraints are a key factor in energy losses, reducing the economic feasibility of technologies. The methodology included a comparative analysis of the electrode materials (Pt, ORTA, graphite, AISI 430, Fe, Ni, Cu, Al) in solutions of H2SO4, NaOH, Na2SO4, and Na2S with the construction and analysis of the anode and cathode Tafel curves to determine kinetic parameters. The results presented by the polarization curves showed a significant dependence of overvoltages on the nature of materials and the composition of electrolytes. Platinum showed the lowest overvoltage values. The ORTA material exhibited ambiguous behavior with a sharp decrease in efficacy in alkaline solutions. Graphite, despite its consistently high overvoltage, confirmed its chemical inertness. Metal electrodes have shown a complex dependence on the electrolyte. The most effective solution was found to be the combination of the AISI 430 stainless-steel cathode with the ORTA anode, which provides the optimal ratio of efficiency and economy. The correct choice of materials and electrolyte significantly increases the energy efficiency of the process.