2022/02/25 by Jussara Barale, Erika Michela Dematteis, Barale, Jussara +13
Chemical Engineering · Engineering · Materials Science · #Catalysis and Hydrodesulfurization Studies #Catalysts for Methane Reforming #FOS: Physical sciences #Hydrogen Storage and Materials #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.2202.12753
openalex publication_date 2022/02/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In the use of hydrogen as large-scale energy vector, metal hydrides based on intermetallic compounds play a key role, thanks to mild temperatures and pressures required for the storage. It is increasingly necessary to develop hydrogen-based devices, and in this work, the intermetallic compound TiFe0.85Mn0.05 is evaluated and selected as H2-carrier for a storage system of 50 kg of H2. A batch of 5 kg of alloy was synthesized at industrial level and characterized through scanning electron microscopy and powder X-ray diffraction, to determine the structure and phase abundance. Moreover, the hydrogen sorption properties were investigated through thermodynamic and kinetic analyses, followed by a long-term cycling study and resistance to O2 and H2O poisoning. Comparing results for alloys with same nominal composition, but prepared either under industrial or laboratory conditions, it was found that the alloy synthesis promotes discrepancies in phase abundance and microstructure and promotes the formation of a passive layer that deeply affect the hydrogen sorption properties. A scheme based on Monte Carlo simulation and structural results was developed to explain the key role of the passive layer (Ti3Fe3O) and of the secondary phases (Ti4Fe2O0.4 and β-Ti80(Fe,Mn)20) in promoting the hydrogenation of the TiFe0.85Mn0.05. A storage system based on this alloy can be integrated with an electrolyser upstream (25 bar) and a fuel cell downstream (1 bar) at 55 ^∘C, storing 1.0 H2 wt.%, displaying fast kinetic, resistance to oxygen, water and nitrogen gas impurities, and stability over more than 250 cycles.