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 containing 1M KOH at 25-degrees-C, using ac impedance and steady-state polarization 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 methanolic solutions it was found that the experimental data could be well approximated by both the fractal and the porous models. The kinetic parameters obtained in the different media were compared to those obtained on polycrystalline nickel.