Achieving Anti‐Disproportionation Performance Enhancement and Distorted Inverse‐Disproportionation Reaction Correction of Zr₂Fe‐Based Hydrogen Isotope Storage Alloys via Element Substitution

Zr₂Fe 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 Zr₂Fe_1-xM_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 Zr₂Fe_1-xM_x-H systems. Notably, Zr₂Fe_0.8Cu_0.2 and Zr₂Fe_0.7Ni_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 (Zr₂Fe) to 184.35 kJ mol^-1 (Zr₂Fe_0.8Cu_0.2) and 192.32 kJ mol^-1 (Zr₂Fe_0.7Ni_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 Zr₂Fe_1-xM_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.