Achieving Anti‐Disproportionation Performance Enhancement and Distorted Inverse‐Disproportionation Reaction Correction of Zr ₂ Fe‐Based Hydrogen Isotope Storage Alloys via Element Substitution

Abstract Zr ₂ Fe alloy is a promising candidate as a tritium‐getter material for the International Thermonuclear Experimental Reactor (ITER), but its practical application is hindered by undesirable inverse disproportionation behavior and poor anti‐disproportionation properties. In this study, theoretical computational screening is utilized to predict the effects of partially substituting Fe with Co, Cu, and Ni on regulating the Zr ₂ Fe _1‐x M _x (M = Co, Cu, Ni; x = 0.1–0.5) hydrogen storage systems. Experimentally, these modifications successfully correct the distorted inverse disproportionation reaction and achieve full reversibility in the Zr ₂ Fe _1‐x M _x‐ H systems. Notably, Zr ₂ Fe _0.8 Cu _0.2 and Zr ₂ Fe _0.7 Ni _0.3 alloys retain excellent hydrogen storage properties, while their kinetic energy barriers of hydriding disproportionation reaction increase significantly from 87.88 kJ mol ⁻¹ (Zr ₂ Fe) to 184.35 kJ mol ⁻¹ (Zr ₂ Fe _0.8 Cu _0.2 ) and 192.32 kJ mol ⁻¹ (Zr ₂ Fe _0.7 Ni _0.3 ), respectively. The corresponding deceleration of hydriding disproportionation kinetics behaviors is clearly visualized by TEM observations. Combined density functional theory analyses reveal that the mechanism underlying enhanced anti‐disproportionation properties in the optimized Zr ₂ Fe _1‐x M _x‐ H systems involves the homogenization and stabilization of Zr─H bonds within the hydrogen storage interstices, along with the effective suppression of disproportionation‐favorable chemical environments.