Novel ternary Ni–Co–Mo based ionic activator for efficient alkaline water electrolysis

•Ternary ionic activator based on Ni, Co and Mo for the cathode.•Energy consumption of alkaline electrolyzer lowered for 17%.•Energy efficiency increased for 15% compared to 6 M KOH.•SEM and UV/VIS reveal deposition of metal ions.

In this manuscript we have presented the results of the use of ternary ionic activator in the alkaline water electrolysis. Novel Ni–Co–Mo based ionic activator was added in-situ to standard electrolyte. Energy consumption of the alkaline electrolyzer was determined at different current densities and elevated temperatures. Energy saving was higher at higher temperatures and higher operating current densities. Results showed that the reduction in energy consumption using Ni–Co–Mo based ionic activator was about 17%, compared to standard 6 M KOH. SEM morphology investigation proved the deposition of nickel, cobalt and molybdenum species on the cathode, greatly increasing the active surface area. UV/VIS spectroscopy was used to monitor changes in the electrolyte composition during the electrolytic process, and results show the decrease in the ionic activator concentration in the 6 M KOH. Our experiments point out a strong possibility of the usage of these ternary ionic activators in industrial alkaline electrolyzers.