Inorganic Electrides: Concepts, Design Principles, Structures, Properties, and Catalytic Applications,

Electrides are a unique class of materials in which electrons are stabilized as anionic species within interstitial sites, endowing them with strong electron-donating ability and low work functions. This Review focuses on how rational structural design governs the catalytic behavior of electrides in sustainable chemical transformations. Electrides are systematically classified by dimensionality (0D/1D/2D/3D) of electron-confined space and stoichiometry (electron-rich, neutral, and deficient) of host materials, and recent design strategies, including high-throughput screening and machine-learning-assisted approaches, are summarized. These strategies enable the development of electrides capable of facilitating kinetically demanding reactions under milder conditions. Representative applications and mechanistic insights in ammonia synthesis/decomposition, CO 2 conversion, and the hydrogen evolution reaction are discussed, highlighting the role of interstitial electrons in activating small molecules. Finally, key challenges related to stability and operando characterization are addressed, and future perspectives toward data-driven discovery and sustainable catalyst design are outlined. This Review systematically classifies inorganic electrides, materials with anionic electrons confined in interstitial sites, by dimensionality and stoichiometry, explores their design via high-throughput and machine-learning methods, and highlights their exceptional catalytic performance in ammonia synthesis/decomposition, CO 2 conversion, and hydrogen evolution, driven by their low work function and high electron-donating ability.