Kinetics of the hydrogen evolution reaction on Ni electrode in synthetic seawater - an alkaline solution

The electrolysis is a technology for production of hydrogen from renewable sources. Modern commercial electrolyzers focus on hydrogen as a chemical, and not as an energy carrier. For the future large-scale production for automotive applications, electrolyzer energy efficiency and the resulting hydrogen quality and cost are important factors that need more attention. The need of ultrapure water in the novel generation of clectrolyzers also increases the cost, and therefore hinders their widespread introduction. The use of seawater could prove to be an economically viable solution. The current research investigates the influence of the contaminants in seawater on the hydrogen evolution reaction on Ni electrode in the temperature range of 25-80 degrees C. The electrochemical kinetic parameters of the reaction Tafel slope, charge transfer coefficient and exchange current density were evaluated by galvanostatic polarization and electrochemical impedance spectroscopy. Long-term stability test results are also described. All results were compared with the results, obtained in KOH prepared with ultrapure water.