Kinetic study of hydrogen evolution reaction on Ni30 Mo70, Co30Mo70, Co30Ni70 and Co10Ni20Mo70 alloy electrodes

The hydrogen evolution reaction on nanocrystalline Ni30Mo70, Co30Mo70, Co30Ni70, and Co10Ni20Mo70, metallic powders prepared by mechanical alloying was investigated with linear polarization and ac impedance methods, in 30 wt.% KOH aqueous solution at room temperature. The formation process and structural properties of these nanocrystalline materials were characterized by X-ray diffraction and transmission electron microscopy. Alloyed powders showed the presence of two phases: an fcc solid solution and intermetallic compounds of Ni, Co and Mo. Based on polarization and ac impedance measurements, an improved electrocatalytic activity for hydrogen evolution reaction was observed in mechanically alloyed Co30Ni70 powders, which is slightly higher than milled metallic Ni powders.