Electrodeposited rhenium–cobalt alloy with high activity for acidic hydrogen evolution reaction

Abstract The development of high-performance electrodes for hydrogen evolution reaction (HER) is essential for commercialization of water electrolyzers. Among the promising candidate for HER catalyst, Re and its oxide display an optimal hydrogen binding energy to that of Pt. Nevertheless, only a few studies have reported the acidic HER catalysts with the high overpotentials (>100 mV at –10 mA cm–2). Furthermore, Re transition metal alloy for the acidic HER catalyst have rarely been reported. Herein, we report a CoRe alloy catalyst for the acidic HER, which was fabricated by electrodeposition on carbon paper (CP) by controlling the electrodeposition. The optimized CoRe/CP electrode exhibited a higher HER activity than those of the other Re-based catalysts with an overpotential of 45.1 mV at −10 mA cm–2. The activation energy for the HER of CoRe/CP, which was calculated from the Arrhenius plot, demonstrated a lower value of 8.99 kJ mol–1 K–1.