Remarkable enhancement in durability of ZrCo alloy against hydrogen induced disproportionation by Ti and Nb co-substitution

Considering the thermodynamic stability of various hydrides, a strategy has been employed to improve the hydrogen isotope storage properties of ZrCo alloy which involves partial co-substitution of Zr with Ti and Nb. Herein, alloys of composition Zr0.8Ti0.2-xNbxCo (x = 0.05, 0.1, 0.15) is prepared, characterized and the effect of Ti and Nb doping on hydrogen storage properties of parent ZrCo alloy is investigated. XRD analysis confirmed the formation of desired pure cubic phase of all the synthesized alloys similar to ZrCo phase. The presence of a single plateau in hydrogen desorption pressurecomposition isotherms confirms single step hydrogen absorption-desorption behavior in Zr0.8Ti0.2-xNbxCo alloys. The equilibrium pressure of hydrogen desorption decreases marginally with increasing Nb content in Zr0.8Ti0.2-xNbxCo alloys which is further corroborated by differential scanning calorimetry measurements. Investigation of hydrogen induced disproportionation behavior in ITER-simulating condition revealed substantial impact of co-substitution of Ti and Nb on anti-disproportionation properties of ZrCo alloy. These remarkable properties make the Ti and Nb co-substituted quaternary alloys a desirable material for hydrogen isotope storage and delivery application.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, the hydrogen isotope storage properties of ZrCo alloy were improved by partially substituting Zr with Ti and Nb. Alloys of composition Zr0.8Ti0.2-xNbxCo (x = 0.05, 0.1, 0.15) were prepared and characterized to investigate the effect of Ti and Nb doping on hydrogen storage properties. XRD analysis confirmed the formation of the desired pure cubic phase in all synthesized alloys, similar to the ZrCo phase. The presence of a single plateau in the hydrogen desorption pressure-composition isotherms confirmed the single-step hydrogen absorption-desorption behavior in Zr0.8Ti0.2-xNbxCo alloys. The co-substitution of Ti and Nb had a significant impact on the anti-disproportionation properties of the ZrCo alloy under hydrogen-induced disproportionation conditions, making the Ti and Nb co-substituted quaternary alloys desirable for hydrogen isotope storage and delivery applications.