Hydrolysis of Mg(BH4)2 and its coordination compounds as a way to obtain hydrogen

Three ligand-stabilized Mg(BH4)2–based complexes have been synthesized and evaluated as potential hydrogen storage media for portable fuel cell applications. The new borohydrides: Mg(BH4)2 × 0.5Et2O and Mg(BH4)2 × diglyme (diglyme – CH3O(CH2)2O(CH2)2OCH3) have been synthesized and examined by X-ray single crystal diffraction method. Hydrolysis reactions of the compounds liberate hydrogen in quantities ranging from 46 to 96% of the theoretical yield. The hydrolysis of Mg(BH4)2 and other borohydrides is also accompanied by the diborane formation. The amount of liberated diborane depends on the Mg-coordination environment. To explain this fact quantum-chemical calculations have been performed. It is shown that formation of Mg-O-Mg-bridges enables the side process of diborane generation. It means that the size and denticity of the ligand directly affects the amount of released diborane. In general, the larger the ligand and the higher its denticity, the smaller is amount of diborane produced. The new compound Mg(BH4)2 × diglyme decomposes without diborane formation that allows one to be considered as a new promising chemical hydrogen storage compound for the practical usage. © 2017 Elsevier B.V.

Authors
Solovev M.V.1 , Chashchikhin O.V.1 , Dorovatovskii P.V.2 , Khrustalev V.N. 3 , Zyubin A.S.1 , Zyubina T.S.1 , Kravchenko O.V.1 , Zaytsev A.A.1 , Dobrovolsky Y.A.1
Publisher
Elsevier B.V.
Language
English
Pages
93-102
Status
Published
Volume
377
Year
2018
Organizations
  • 1 Institute of Problems of Chemical Physics RAS, Chernogolovka Moscow Region, 142432, Russian Federation
  • 2 NRC Kurchatov Institute, 1 Acad. Kurchatov Sq., Moscow, 123182, Russian Federation
  • 3 Department of Inorganic Chemistry, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklay Str., Moscow, 117198, Russian Federation
Keywords
Borohydride hydrolysis; Chemical hydrogen storage; Diborane; Fuel cell; Magnesium borohydride; New coordination compounds
Date of creation
19.10.2018
Date of change
19.10.2018
Short link
https://repository.rudn.ru/en/records/article/record/6838/