2023/07/23 by Satish Kumar Verma, Verma, S. K., Shashank Mishra +5
Engineering · Materials Science · #Catalysis and Hydrodesulfurization Studies #FOS: Physical sciences #Hydrogen Storage and Materials #Magnesium Alloys: Properties and Applications #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.2307.12240
openalex publication_date 2023/07/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Magnesium hydride (MgH2) is the mostly used material for solid-state hydrogen storage. However, their slow kinetics and highly unfavorable thermodynamics make them unsuitable for the practical applications. The current study describes the unusual catalytic action of a new class of catalyst, a high-entropy alloy (HEA) of Al20Cr16Mn16Fe16Co16Ni16, on the de/re-hydrogenation properties of MgH2. The onset desorption temperature of MgH2 is reduced significantly from 376 °C (for pristine MgH2) to 338 degC when it is catalyzed with a HEA-based catalyst. On the other hand, a fast de/re-hydrogenation kinetics of MgH2 was observed during the addition of HEA-based catalyst. It ab sorbs 6.1 wt% of hydrogen in just 2 minutes at a temperature of 300 degC under 10 atm hydrogen pressure and desorbs ~ 5.4 wt% within 40 minutes. At moderate temperatures and low pressure, the HEA-based catalyst reduced desorption temperatures and improved re-hydrogenation kinetics. Even after 25 cycles of de/re-hydrogenation, the storage capacity of MgH2 catalyzed with the leached version of HEA degrades negligibly.