|Conţinutul numărului revistei|
| SM ISO690:2012|
VERNICKAITE, E.; BERSIROVA, Oksana; CESIULIS, Henrikas; TSYNTSARU, Natalia. Design of highly active electrodes for hydrogen evolution reaction based on mo-rich alloys electrodeposited from ammonium acetate bath. In: Coatings. 2019, nr. 2(9), p. 0. ISSN 2079-6412.
|Numărul 2(9) / 2019 / ISSN 2079-6412|
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.
Co-Mo, Electrocatalysis, Electrodeposition, Fe-Mo alloys, Hydrogen evolution reaction, Ni-Mo