Isotope effect on hydrogen storage properties of Ti and Nb co-substituted ZrCo alloy

In our previous study, we showed that the anti-disproportionation properties of Zr0.8Ti0.2-xNbxCo alloys were remarkably improved by the co-substitution of Zr with Ti and Nb. However, the practical application of these alloys in handling of hydrogen isotopes ne-cessitates the first hand knowledge of hydrogen isotope effect. Herein, we discuss the hydrogen isotope effect on storage properties of Zr0.8Ti0.2-xNbxCo alloys. According to PCT measurements on desorption of deuterium from the Zr0.8Ti0.2-xNbxCo deuterides and comparison with corresponding hydrides, the deuterides require relatively lower temper-ature to achieve the desired equilibrium pressure. DSC measurements reveal a significant decrease in the activation energy for hydrogen/deuterium desorption reactions when Zr is substituted with Ti and Nb. Furthermore, it is observed that the activation energy of deuterium desorption is lower than the desorption of hydrogen from analogous hydride. Isotope effect on isothermal disproportion studies on Zr0.8Ti0.2-xNbxCo-deuterides divulge that Zr0.8Ti0.2-xNbxCo-deuterides have superior anti-disproportionation properties over corresponding hydrides, and further improvement is anticipated for the Zr0.8Ti0.2-xNbxCo- tritides. This study revealed the significant impact of Ti and Nb co-substitution on hydrogen isotope storage properties of Zr0.8Ti0.2-xNbxCo alloys, making them potential candidates for handling hydrogen isotopes.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.