Electrochemical characterization of the Ni-W catalyst formed in situ during alkaline electrolytic hydrogen production-Part II

Abstract

Objective of this work was to investigate the electrocatalytic efficiency using quasi-potentiostatic, galvanostatic and impedance spectroscopy techniques of the Ni-W catalysts obtained by in situ electrodeposition in an alkaline, GM KOH, electrolyser. Synergetic effect is observed, with its maximum at industrial conditions (high temperature and current density). The Tafel slopes are similar to 120 mV and exchange current densities are in the range of 10(-4) mA cm(-2). Results are presented to show the Tafel slopes, the exchange current densities, the apparent energy of activation and the apparent electrochemical surface of the in situ formed Ni-W catalyst. Obtained results could have significant impact on the industrial process for the alkaline hydrogen production and suggest to good catalytic performance not only from the increase of the real surface area of the electrodes, but also from the true catalytic effect. (C) 2011 Elsevier B.V. All rights reserved.