Nickel-cobalt electrodeposited alloys for hydrogen evolution in alkaline media

A study on the electrocatalytic Performances of nickel-cobalt alloys for hydrogen evolution in alkaline media has been carried out. After preparing, by electrodeposition on aluminium net supports, Ni-Co alloys of various compositions ranging from 0 to 100% Ni, the alloys were examined by polarization measurements, to evaluate their discharge potential and Tafel parameters. Moreover a durability test has been done on the alloys showing, among all, the best performance, The hydrogen over-potential appears to be lower in the case of Ni concentrations ranging between 35 and 59 weight percent. The synergism among the nickel catalytic properties, having low hydrogen over-potential and high hydrogen adsorption of cobalt, is best realized in this conditions and allow obtaining a largest value of exchange current density. (C) 2009 International Association for Hydrogen Energy.