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 reactio n (her) on nickel in 1.0 mol dm (-3) NaOH solution was studied. In this art icle, four sets of experiments were done in a non-isothermal cell. In all e xperiments only the compartment of the Ni working electrode was thermostate d at 278.5, 303.0, 313.0 and 323.0 K, while the reference electrode (Hg \ H gO) was held constantly at 298.0 K. It was found that the transfer coeffici ent, alpha decreased with temperature. Using the calculated chemical rate c onstants and the corresponding partial standard rate constants for the Volm er, Heyrovsky and Tafel steps in both directions and the corresponding Arrh enius relationship, the chemical enthalpies of activation and the correspon ding pre-exponential factors were determined. It was demonstrated that the limiting current for the her at potentials more negative than - 1.6 V occur s because the her takes place as an activationless process. (C) 2001 Publis hed by Elsevier Science B.V.