Electrocatalytic activity of Ni-Mo-Cu and Ni-Co-Cu alloys for hydrogen evolution reaction in alkaline medium

Tri-component Ni-Co-Cu and Ni-Mo-Cu alloys are electrodeposited depending on current density, temperature and copper ion electrolyte concentration. In both systems hydrogen evolution reaction (HER) is studied by polarization dependences and electrochemical impedance spectroscopy (EIS) in 6M KOH. It is shown that the incorporated copper quantity is significant for alloy catalytic activity. The lowest overvoltage and charge transfer resistor values for HER, and respectively, the best catalytic activity, is exhibited by Ni43Co37Cu20 and Ni57Mo27Cu16 alloys. The high electrode activity of Mo-alloys is associated with a well developed surface area whereas in Co-alloys it is attributed also to Ni-Co synergism. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.