UNIGE document Scientific Article
previous document  unige:92822  next document
add to browser collection

Synthesis, structure and properties of new bimetallic sodium and potassium lanthanum borohydrides

Payandeh GharibDoust, SeyedHosein
Heere, Michael
Sørby, Magnus H.
Ley, Morten B.
Ravnsbæk, Dorthe B.
Hauback, Bjørn C.
Jensen, Torben R.
Published in Dalton Transactions. 2016, vol. 45, no. 47, p. 19002-19011
Abstract Two new bimetallic sodium or potassium lanthanum borohydrides, NaLa(BH4)4 and K3La(BH4)6, are formed using La(BH4)3 free of metal halide by-products. NaLa(BH4)4 crystallizes in an orthorhombic crystal system with unit cell parameters, a = 6.7987(19), b = 17.311(5), c = 7.2653(19) Å and space group symmetry Pbcn. This compound has a new structure type built from brucite-like layers of octahedra (hcp packing of anions) with half of the octahedral sites empty leading to octahedral chains similar to rutile (straight chains) or α-PbO2 (zig-zag chains). K3La(BH4)6 crystallizes in the monoclinic crystal system with unit cell parameters a = 7.938(2), b = 8.352(2), c = 11.571(3) Å, β = 90.19(6)° and space group P21/n with a double-perovskite type structure. Thermogravimetric analysis shows a mass loss of 5.86 and 2.83 wt% for NaLa(BH4)4 and K3La(BH4)6, respectively, in the temperature range of room temperature to 400 °C. Mass spectrometry shows that hydrogen release starts at 212 and 275 °C for NaLa(BH4)4 and K3La(BH4)6, respectively and confirms that no diborane is released. Sieverts’ measurements reveal that 2.03 and 0.49 wt% of hydrogen can be released from the NaLa(BH4)4 and K3La(BH4)6, respectively, during the second hydrogen desorption cycle at the selected physical condition for hydrogen absorption.
Keywords Hydrogen storageMetal hydridePowder diffraction
Full text
Article (Published version) (3.8 MB) - document accessible for UNIGE members only Limited access to UNIGE
Other version: http://xlink.rsc.org/?DOI=C6DT03671F
Research group Groupe Cerny
(ISO format)
PAYANDEH GHARIBDOUST, SeyedHosein et al. Synthesis, structure and properties of new bimetallic sodium and potassium lanthanum borohydrides. In: Dalton Transactions, 2016, vol. 45, n° 47, p. 19002-19011. https://archive-ouverte.unige.ch/unige:92822

63 hits

0 download


Deposited on : 2017-03-27

Export document
Format :
Citation style :