A New Complex Borohydride LiAl(BH4)2Cl2

Dolotko, Oleksandr (ORCID:0000000263860281); Kobayashi, Takeshi (ORCID:0000000263660925); Hlova, Ihor Z.; Gupta, Shalabh; Pecharsky, Vitalij K.

doi:10.3390/inorganics9050035

DOE OSTI · 2397359

A New Complex Borohydride LiAl(BH4)2Cl2

Dolotko, Oleksandr (ORCID:0000000263860281)·Kobayashi, Takeshi (ORCID:0000000263660925)·Hlova, Ihor Z.·Gupta, Shalabh·Pecharsky, Vitalij K.

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Abstract

A new mixed alkali metal–aluminum borohydride LiAl(BH4)2Cl2 has been prepared via mechanochemical synthesis from the 2LiBH4–AlCl3 mixture. Structural characterization, performed using a combination of X-ray powder diffraction and solid-state NMR methods, indicates that the LiAl(BH4)2Cl2 phase adopts a unique 3D framework and crystallizes in an orthorhombic structure with the space group C2221, a = 11.6709(6) Å, b = 8.4718(4) Å, c = 7.5114(3) Å. The material shows excellent dehydrogenation characteristics, where hydrogen evolution starts at Tons = 70 °C, releasing approximately 2 wt.% of nearly pure (99.8 vol.%) hydrogen and a very small amount (~0.2 vol.%) of diborane. When compared to halide-free mixed alkali metal–aluminum borohydrides, the presence of Al‒Cl bonding in the LiAl(BH4)2Cl2 structure likely prevents the formation of Al(BH4)3 upon decomposition, thus suppressing the formation of diborane.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY X-ray diffraction crystal structure hydrides hydrogen storage solid-state NMR

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Dolotko, Oleksandr (ORCID:0000000263860281), Kobayashi, Takeshi (ORCID:0000000263660925), Hlova, Ihor Z., Gupta, Shalabh, Pecharsky, Vitalij K.. 2021-05-04. A New Complex Borohydride LiAl(BH4)2Cl2. https://doi.org/10.3390/inorganics9050035

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