Electrocatalytic activity of ZnCoMo based ionic activators for alkaline hydrogen evolution—Part II

Nickel electrodes are widely used in industrial water electrolysis cells for electrochemical production of hydrogen. To avoid extensive deactivation problems and enhance the efficiency of the electrolyser cathode, in this work in situ activation is proposed using ionic activator (i.a.) based on combination of three d-metals: Zn, Co and Mo. Polarization curves, obtained at different temperatures (303–343 K), reveal that the addition of ZnCoMo based i.a. did not change reaction mechanism when compared to the HER mechanism on nickel cathode in standard electrolyte. The electrochemical impedance spectroscopy measurements were employed to further investigate the origin of obtained electrocatalytic effect on the HER. The morphology of obtained coatings was examined by scanning electron microscopy.

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► In situ activation is proposed using ionic activators based on of Zn, Co and Mo.
► Polarization curves revel no change reaction mechanism of the HER.
► The roughness factor values for the ZnCoMo based i.a. are very high.
► SEM images show that the obtained deposits are mostly based on cobalt.