HYDROGEN EVOLUTION REACTION AT COMPOSITE-COATED RANEY-NICKEL ELECTRODES IN AQUEOUS AND AQUEOUS-METHANOLIC SOLUTIONS

The hydrogen evolution reaction was studied at composite-coated Raney nickel electrodes in aqueous and aqueous methanolic solutions containi ng 1M KOH at 25-degrees-C, using ac impedance and steady-state polariz ation techniques. In aqueous solutions, the experimental results were analyzed by the constant-phase element (CPE) and the porous electrode models, and the resulting parameters were compared. In aqueous methano lic solutions it was found that the experimental data could be well ap proximated by both the fractal and the porous models. The kinetic para meters obtained in the different media were compared to those obtained on polycrystalline nickel.