The hydrogen evolution reaction on codeposited Ni–hydrogen storage intermetallic particles in alkaline medium

The hydrogen evolution reaction (HER) was studied on Ni–LaNi5 and Ni–MmNi3.4Co0.8Al0.8 electrode materials in 1 mol dm−3 NaOH solution. The steady-state polarization curves and electrochemical impedance spectroscopy experimental data showed a pronounced improvement in HER kinetics when these electrode materials were used. The electrochemical results are in accordance with the Volmer–Heyrovsky mechanism. The kinetic results indicate a more effective improvement in the Heyrovsky step, suggesting an electrocatalytic synergistic effect of the hyper-electronic character of the Ni and the hypo-electronic character of the rare-earth element on the electrode surface.