Progress and perspectives on hydrogen embrittlement of high-entropy alloys

Hydrogen has been recognized as a promising clean and efficient energy carrier that will be key to achieving a net-zero emission future by replacing fossil fuels. The forthcoming decades will see the extensive utilization of green hydrogen across key sectors, such as transportation, metallurgy, and energy. However, the application of hydrogen faces significant challenges in its transport and storage, because hydrogen embrittles metals, compromising the structural integrity of critical components. High-entropy alloys (HEAs) demonstrate outstanding physicochemical and mechanical properties, e.g., superior resistance to hydrogen embrittlement (HE), positioning them as promising structural materials for hydrogen-related industries. This review comprehensively summarizes recent advances in understanding HE in HEAs. We systematically discuss dominant HE mechanisms and their manifestations across various HEA systems, including typical face-centered-cubic, body-centered-cubic, and dual-phase alloys. The interactions between microstructural features — such as dislocations, grain boundaries, phase interfaces, and precipitates — and hydrogen are critically discussed. Furthermore, we outline current strategies for enhancing HE resistance in HEAs through the alloy design, microstructural engineering, and interface modification. Looking forward, integrating multiscale experimental characterization with computational modeling will be essential to unravel the complex hydrogen behaviors in HEAs and to guide the development of HE-resistant alloys. © 2026 Elsevier B.V.