Development of electrode morphologies of interest in electrocatalysis Part 2: Hydrogen evolution reaction on macroporous nickel electrodes

The current-potential dependence for the hydrogen evolution reaction (HER) was determined on macroporous nickel electrodeposits with toughness factors ranging between 7 and 1700 in alkaline solution. It has been demonstrated that the active electrodic area is conditioned by the presence of occluded hydrogen gas inside the pores. Starting from measurements of the total real surface area and the polarization resistance, the active area for the HER (wetted area) was determined. On the basis of these results, it has been concluded that the electrocatalytic activity is the same For all these electrodeposits. The kinetic parameters corresponding to the Volmer-Heyrovsky-Tafel mechanism were evaluated and critically compared with those previously determined for smooth nickel electrodes in the same experimental conditions. Besides, the apparent electrocatalytic activity was compared with that of a Raney-Nickel electrode. (C) 2001 Elsevier Science S.A. All rights reserved.