Mo, Y.Guan, X.Wang, S.Duan, X.2025-05-012025-05-012025Chemical Science, 2025; 16(4):1652-16762041-65202041-6520https://hdl.handle.net/2440/144355High-entropy spinel (HES) compounds, as a typical class of high-entropy materials (HEMs), represent a novel frontier in the search for next-generation catalysts. Their unique blend of high entropy, compositional diversity, and structural complexity offers unprecedented opportunities to tailor catalyst properties for enhanced performance (i.e., activity, selectivity, and stability) in heterogeneous reactions. However, there is a gap in a critical review of the catalytic applications of HESs, especially focusing on an in-depth discussion of the structure–property–performance relationships. Therefore, this review aims to provide a comprehensive overview of the development of HESs in catalysis, including definition, structural features, synthesis, characterization, and catalytic regimes. The relationships between the unique structure, favorable properties, and improved performance of HES-driven catalysis are highlighted. Finally, an outlook is presented which provides guidance for unveiling the complexities of HESs and advancing the field toward the rational design of efficient energy and environmental materials.en© 2025 The Author(s). Published by the Royal Society of Chemistry. Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.catalysis; catalysts; entropy; spinelJournal article10.1039/d4sc05539j725792Mo, Y. [0000-0002-3267-3926]Wang, S. [0000-0002-1751-9162]Duan, X. [0000-0001-9635-5807]