On the kinetics of the hydrogen evolution reaction on nickel in alkaline solution - Part II. Effect of temperature

The effect of temperature on the kinetics of the hydrogen evolution reaction (her) on nickel in 1.0 mol dm (-3) NaOH solution was studied. In this article, four sets of experiments were done in a non-isothermal cell. In all experiments only the compartment of the Ni working electrode was thermostated at 278.5, 303.0, 313.0 and 323.0 K, while the reference electrode (Hg \ HgO) was held constantly at 298.0 K. It was found that the transfer coefficient, alpha decreased with temperature. Using the calculated chemical rate constants and the corresponding partial standard rate constants for the Volmer, Heyrovsky and Tafel steps in both directions and the corresponding Arrhenius relationship, the chemical enthalpies of activation and the corresponding pre-exponential factors were determined. It was demonstrated that the limiting current for the her at potentials more negative than - 1.6 V occurs because the her takes place as an activationless process. (C) 2001 Published by Elsevier Science B.V.