The hydrogen evolution reaction (HER) on Ni electrode in artificial seawater was investigated by steady-state
polarisation curves and electrochemical impedance spectroscopy methods at the room temperature and at high
temperatures (30–60oC). The electrochemical kinetics parameters of the HER – Tafel slope, charge transfer coefficient
and exchange current density – were evaluated in accordance with the potential scan direction and temperature. The
Tafel slopes are significantly higher than 120 mV/decade and they increase with the increasing of the solution
temperature. The charge transfer coefficient is lower than 0.5 and it decreases with temperature. The exchange current
density has a magnitude order of 10-5 A·cm-2 and its value is increasing with increasing solution temperature. The
activation energy of the HER has a moderate value, that slowly decreases with the cathodic polarisation increase. The
HER is controlled by the charge transfer step and by the mass transfer of the intermediate reaction product Hads on the
electrode surface
