Structure and hydrogenstorage properties of the first rare-earth metal borohydride ammoniate: Y(BH₄)₃·4NH₃

Tailoring the Properties of Ammine Metal Borohydrides for Solid‐State Hydrogen Storage

“…s8_150 only reveals broad signals between 1500 and 500 cm À1 , which may be assigned to BÀN bonds in accord with previous investigations of ammine metal borohydrides. [23,44] Hydrogen uptake has also been examined for s7_150 at T = 250 8C, p(H 2 ) = 145 bar for 16 h. However, no changes in the measured FTIR or PXD data for the sample before and after this treatment were observed ( Figure S25 and S26), reflecting that hydrogen uptake did not occur at these conditions.…”

“…[13,22] A range of other ammine metal borohydrides have been synthesized by a metathesis reaction of the ammine metal chloride, MCl m ·nNH 3 and lithium borohydride, LiBH 4 . [23][24][25] The resulting samples contain significant amounts of LiCl acting as a 'deadweight', which reduces the hydrogen storage capacity and possibly also reversibility due to formation of inert metal chlorides. Release of ammonia is detrimental for many applications, for example, in low-temperature polymer electrolyte membrane fuel cells, and needs to be reduced by proper materials design, which was recently addressed by a series of ammine magnesium borohydrides, Mg(BH 4 ) 2 ·nNH 3 (n = 1, 2, 3).…”

Resolving the stability and structure of strontium chloride amines from equilibrium pressures, XRD and DFT

“…Ammonia stored in a safe manner is an attractive candidate as an energy carrier in vehicles [2e5] and as an ammonia reservoir for the selective catalytic reduction (SCR) of NO x gases in the vehicular exhaust [6]. Addition of metal borohydrides like LiBH 4 [7,8] or Mg(BH 4 ) 2 [9,10] to form the amine metal borohydrides (AMBs), enables a promising pathway for direct release of hydrogen upon heating, which is currently under intense investigation [11,12]. One of the most studied members of the amine family is Mg(NH 3 ) 6 Cl 2 [1,13], due to a high volumetric and gravimetric hydrogen capacity as well as good ab-and desorption kinetics [14,15].…”

Improved dehydrogenation properties of Mg(BH4)2·2NH3 combined with LiAlH4

“…Mg(BH 4 ) 2 $2NH 3 and Al(BH 4 ) 3 $6NH 3 were found to dehydrogenate with only a small amount of ammonia [21], and Zn(BH 4 ) 2 $2NH 3 presented a pure hydrogen release upon decomposition [22]. These results suggest that the dehydrogenation properties of AMBs could be tuned extensively using different metal cations, which have probably different electronegativity and result in the different crystal structure of AMBs [15,23].…”