The effects of filamentary Ni, graphene and lithium amide (LiNH2) additives on the dehydrogenation behavior of mechano-chemically synthesized crystalline manganese borohydride (Mn(BH4)2) and its solvent filtration/extraction
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Date
2018-04-01
Authors
Varin, Robert A.
Bidabadi, Amirreza Shirani
Polanski, Marek
Biglari, Mazda
Stobinski, Leszek
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Dehydrogenation properties of mechano-chemically synthesized crystalline Mn(BH4)2 hydride without and with ultrafine filamentary carbonyl nickel (Ni), graphene and LiNH2 were investigated. It is reported for the first time that all additives suppressed the release of B2H6 with the filamentary Ni additive being the most effective suppressor of B2H6. In DSC, the decomposition peak of Mn(BH4)2 was endothermic. The estimated apparent activation energy for isothermal dehydrogenation was dramatically reduced to 44.9 ± 4.3 kJ/mol for the 5 wt.% LiNH2 additive from about 76–81 kJ/mol range for the additive-free sample and 5 wt.% filamentary Ni and graphene additives. The most striking finding, that has never been reported in the literature, is that the process of solvent filtration and extraction of the mechano-chemically synthesized (Mn(BH4)2/LiCl) sample, resulted in the crystallization of a dimetallic borohydride solvate [{Li(Et2O)2}Mn2(BH4)5] instead of crystalline Mn(BH4)2. Its dehydrogenation behavior was investigated isothermally and by TGA/DSC.
Description
The final publication is available at Elsevier via http:/dx.doi.org/10.1016/j.materresbull.2017.12.051 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Keywords
Additives, Dehydrogenation behavior, Hydride hydrogen storage, Manganese borohydride Mn(BH), Mechano-chemical activation synthesis, Solvent filtration/extraction