Title Design of highly active electrodes for hydrogen evolution reaction based on mo-rich alloys electrodeposited from ammonium acetate bath /
Authors Vernickaitė, Edita ; Bersirova, Oksana ; Cesiulis, Henrikas ; Tintaru, Natalia
DOI 10.3390/COATINGS9020085
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Is Part of Coatings.. Basel : MDPI. 2019, vol. 9, iss. 2, art. no. 85, p. [1-15].. ISSN 2079-6412
Keywords [eng] Co-Mo ; Electrocatalysis ; Electrodeposition ; Fe-Mo alloys ; Hydrogen evolution reaction ; Ni-Mo
Abstract [eng] The given research was driven by prospects to design Mo-rich coatings with iron group metals electrodeposited from a highly saturated ammonium acetate bath. The obtained coatings could be employed as prominent electrodes for the hydrogen evolution reaction (HER). It was found that the Mo content in Ni-Mo alloys can be tuned from 30 to 78 at.% by decreasing the molar ratio [Ni(II)]:[Mo(VI)] in the electrolyte from 1.0 to 0.25 and increasing the cathodic current density from 30 to 100 mA/cm2. However, dense cracks and pits are formed due to hydrogen evolution at high current densities and that diminishes the catalytic activity of the coating for HER. Accordingly, smoother and crack-free Ni-54 at.% Mo, Co-52 at.% Mo and Fe-54 at.% Mo alloys have been prepared at 30 mA/cm2. Their catalytic behavior for HER has been investigated in a 30 wt.% NaOH solution at temperatures ranging from 25 to 65 °C. A significant improvement of electrocatalytic activity with increasing bath temperature was noticed. The results showed that the sequence of electrocatalytic activity in alkaline media decreases in the following order: Co-52 at.% Mo > Ni-54 at.% Mo > Fe-54 at.% Mo. These peculiarities might be linked with different catalytic behavior of formed intermetallics (and active sites) in electrodeposited alloys. The designed electrodeposited Mo-rich alloys have a higher catalytic activity than Mo and Pt cast metals.
Published Basel : MDPI
Type Journal article
Language English
Publication date 2019
CC license CC license description