Electrochemical performance of hydrogen evolution reaction of Ni–Mo electrodes obtained by mechanical alloying

Abstract

Electro active Ni–Mo electrodes have been prepared by mechanical alloying and pressure-less sintering (1173 K) Ni and Mo powders. The electrochemical performance of obtained electrodes has been evaluated in KOH 30% at 343 K as a function of the milling time, applied pressure for green compaction as well as the effect conferred by the addition of a process control agent (PCA). Cathodic slope of the best specimen is 279 mV/ dec . Faster reaction kinetics is observed for the specimens treated with PCA addition. The longer milling time and applied pressure on the specimens the better cathodic response. The activation overpotential, i.e. cathodic-Tafel slopes found at high overvoltages are in the range of 274– 481 mV/ dec , whereas the exchange current density for the hydrogen evolution reaction ranged from 27.3 to 1.4 mA/ cm 2 .