Nanowire-template-assisted NiMo catalyst for efficient hydrogen evolution in anion-exchange membrane water electrolyzers

초록

The development of efficient electrocatalysts for the alkaline hydrogen evolution reaction (HER) is of paramount importance for addressing energy challenges and achieving decarbonization. This paper reports the preparation of low cost NiMo/Co-nanowire (NW)/carbon paper (CP) catalysts using a simple two-step electrodeposition process. The Co-NW template was prepared by optimizing the Co deposition potential and time on a CP substrate. Next, binary NiMo was electrodeposited onto the Co-NW templates to prepare NiMo/Co-NW/CP catalysts. The developed catalyst exhibited high performance toward the HER in an alkaline environment, necessitating a mere 85 mV overpotential in 1 M potassium hydroxide to achieve a current density of −10 mA cm−2 and sustaining high stability over 100 h at the same operating current density. This excellent performance can be attributed to a 1.66-fold increase in active site exposure, from 24.5 mF cm−2 to 40.8 mF cm−2, due to the use of the Co-NW template, as substantiated by electrochemical double-layer capacitance measurements. Consequently, the HER activity of NiMo/Co-NW/CP was markedly enhanced in relation to that of NiMo/CP. The NiMo/Co-NW/CP catalyst was employed as a cathode of an anion-exchange membrane water electrolyzer, which exhibited an exceptional performance of 1.52 A cm−2 at 2.0 Vcell. © 2025 Elsevier B.V.

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