High‐Performance FeRu Alloy Electrocatalyst Integrated with a Mo Substrate for Hydrogen Evolution Reaction in Seawater

Abstract The production of hydrogen from seawater offers a potential pathway to accomplish sustainable energy solutions. However, this process is impeded by the sluggish kinetics of the hydrogen evolution reaction (HER) and the corrosive nature of seawater. In this work, an FeRu alloy electrocatalyst integrated with a Mo substrate (FeRu/MoO 2 @Mo) is developed, specifically designed for HER in both alkaline and seawater environments. The FeRu/MoO 2 @Mo catalyst demonstrated remarkable performance, achieving overpotentials of only 22, 42, and 65 mV in alkaline solution, simulated seawater, and real seawater at 10 mA cm −2 . Moreover, the FeRu/MoO 2 @Mo electrocatalyst exhibited long‐term stability for HER, maintaining its activity for at least 400 h under conditions of 1 m KOH. In situ Raman spectroscopy and theoretical calculations revealed incorporation of Fe reduces the density of states near the Fermi level of Ru, thereby optimizing hydrogen adsorption–desorption behavior and enhancing the HER activity. This work offers a scalable and cost‐effective strategy for the development of efficient non‐platinum catalysts.