Influence of the phase evolution and hydrogen storage behaviors of Mg-RE alloy by a multi-valence Mo-based catalyst

• Published in: Journal of energy storage Vol. 58; p. 106397
• Main Authors: Wang, Shuai, Yong, Hui, Yao, Jiwei, Ma, Jiangwei, Liu, Baosheng, Hu, Jifan, Zhang, Yanghuan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2023
• Subjects: Catalysts; Hydrogen storage; Kinetics; Microstructure; Thermodynamics; Thermodynamics; Hydrogen storage; Kinetics; Catalysts; Microstructure
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2022.106397

The Mg90Ce5Y5 alloy was prepared by the vacuum induction melting, and Mo, MoO2 and MoO3 were doped into it by mechanical ball-milling, respectively. Their microstructure, phase evolution, as well as hydrogen storage thermodynamic and kinetic properties were investigated by XRD, SEM, TEM, PCT and DSC method. The result shows that the internal phases of the Mo catalyzed alloy become MgH2, CeH2.73, YH3 and Mo phases after hydrogen absorption, while the hydrogenated alloy consists of MgH2, CeO2, YH3, MgO and Mo phases for the MoO2 catalyzed alloy and MgH2, MgO, CeO2, Y2O3 and Mo phases for the MoO3 catalyzed alloy. REDOX reaction occurred between MoO2, MoO3 and the inner phase of the alloy, respectively. In comparison, Mo catalyzed alloy has a higher hydrogen absorption saturation ratio, but the MoO2 catalyzed alloy needs a shorter time than Mo and MoO3 catalyzed alloys to release H2, and the dehydrogenation activation energy (Edes) of the samples show an increasing trend in the following order: MoO2 catalyzed alloy (110.18 kJ/mol)<MoO3 catalyzed alloy (113.72 kJ/mol)<Mo catalyzed alloy (114.24 kJ/mol). The initial dehydrogenation temperature and peak temperature of the MoO2 catalyzed alloy are the lowest, which means it has the best catalytic effect on the dehydrogenation kinetics of the alloy. •The Mg-based composite catalyzed by multi-valence Mo-based catalyst is prepared.•The dehydrogenation temperature of the material is reduced to about 473 K.•The activation energy of Mg-based alloy is reduced to about 110 kJ/mol.