Electride‐Induced Electronic Modulation of Ruthenium Catalyst for Highly Efficient Alkaline Hydrogen Evolution

ABSTRACT Electrides, featuring localized electrons serving as anionic species, have attracted increasing attention for their catalytic potential. However, their application as supports for hydrogen evolution reaction (HER) electrocatalysts has remained elusive, primarily due to their high chemical reactivity under aqueous conditions. In this study, we report the rational design of a robust electride‐supported HER catalyst, Ruthenium (Ru)/Nd ₂ ScSi ₂ , which delivers outstanding performance with an overpotential of only 48 mV at −10 mA cm ⁻² in 1.0 m KOH, along with excellent long‐term stability. In‐depth mechanistic investigations, combining in situ spectroscopic analyses with density functional theory calculations, reveal that negatively charged Ru species anchored on the electride surface are pivotal in promoting HER activity. These anionic Ru sites facilitate water dissociation and modulate hydrogen adsorption by reshaping the electronic landscape and tuning the active sites. Our findings highlight the feasibility of leveraging the unique electronic characteristics of electrides to modulate supported metal catalysts, offering a new paradigm for the design of high‐efficiency HER electrocatalysts through electronic structure engineering.