LOW HYDROGEN OVERPOTENTIAL NANOCRYSTALLINE NI-MO CATHODES FOR ALKALINE WATER ELECTROLYSIS

Nanocrystalline fcc Ni(x)Mo1-x (x = 0.60, 0.85 atom percent) metallic powders prepared by high energy mechanical alloying were found to possess electrocatalytic activities for the hydrogen evolution reaction in 30 weight percent KOH at 70-degrees-C equivalent to that of the best electrocatalysts. The formation process and the structural properties of these nanocrystalline alloys were investigated. The active phase is a metastable solid solution of Mo in fcc Ni whose electrocatalytic activity is associated with the reduction in the size of the crystallites and correlates with the expansion of the Ni lattice.