Xue Ke, Yang Zhang, Fulai Qi, Qian Zhang, Xinqiang Wang, Yanxia Liu, Ke Wang, Jindou Shi, Zichao Shen, Mingchang Zhang, Yufeng Yang, Yufeng Yang, Fan Gao, Wengang Cui, Zhenglong Li, Yufeng Yang, Yufeng Yang, Lixian Sun, J. F. Chen, Hongge Pan
ABSTRACT Magnesium hydride (MgH 2 ) is widely regarded as a highly promising solid‐state hydrogen storage material. However, its practical application is severely constrained by high operating temperatures and sluggish hydrogen absorption/desorption kinetics arising from multistep reaction energy barriers. Here, we rationally tailor a quinary Ti‐based rutile‐type high‐entropy oxide to overcome these intrinsic limitations for the first time. The onset dehydrogenation temperature of the hybrid reduces to 195°C, which is 163°C lower than that of pristine MgH 2 . The composite releases 5.88 wt.% H 2 within 10 min at 250°C, accompanied by a 58% reduction in the apparent dehydrogenation activation energy. Moreover, a 1.84 wt.% H 2 uptake can be achieved within only 20 s at room temperature. The coexistence of various multivalent metal cations, lattice distortions, abundant defects, and oxygen vacancies in (TiNbCrTaFe)O 2 substantially reduces the multi‐step reaction energy barriers during MgH 2 de/hydrogenation, enabling the overall kinetics to surpass those of all previously reported high‐entropy catalyst‐modified MgH 2 systems. This work expands the compositional design space and application scope of high‐entropy oxides and provides a viable strategy for advanced hydrogen storage and catalytic systems.