Improved catalytic activity of MoxNiyAlz thin films as electrocatalyst for hydrogen evolution reaction in alkaline media

In the present article, we studied the catalytic activity of magnetron-sputtered Mo_xNi_yX_z (where X = Al, Co, Cr, Cu, Fe, W) thin films for the hydrogen evolution reaction (HER) in 1 M NaOH. Thin-film electrocatalysts were prepared at 25 °C and 800 °C and characterized by SEM-EDX and XRD analyses. The Mo₈₀Ni₅Al₁₅(800 °C)   electrocatalyst demonstrated the best HER overpotential (-181 mV) among all tested ternary systems. XRD analysis revealed that only the Mo₈₀Ni₅Al₁₅ thin films prepared at 800 °C exhibited the fcc phase, while less active compositions contained only the bcc phase. Electrochemical impedance spectroscopy results were consistent with cyclic voltammetry measurements. Chronoamperometry showed that the HER activity of Mo₈₀Ni₅Al₁₅(800 °C) remained stable after a slight initial drop, whereas the activity of Ni catalysts nearly halved over the same time frame. These findings suggest that Mo₈₀Ni₅Al₁₅(800 °C)   could serve as a promising alternative to industrial Ni-based catalysts for alkaline water electrolyzers.