Significantly improved de/rehydrogenation properties of lithium borohydride modified with hexagonal boron nitride

Abstract

The remarkable hydrogen de/absorption properties of lithium borohydride are achieved by mechanically milling LiBH 4 with hexagonal boron nitride (h-BN). It is found that the dehydrogenation properties of LiBH 4 are improved with increasing the amount of h-BN. The 30 mol% h-BN doped LiBH 4 composite starts to release hydrogen from just 180 C, which is 100 C lower than the onset dehydrogenation temperature of ball milled LiBH 4 . Moreover, the 30 mol% h-BN doped LiBH 4 composite can release 12.6 wt% hydrogen in 2 h at 400 C, while only 0.98 wt% H 2 is gained from ball milled LiBH 4 . The apparent activation energy (E a ) of hydrogen desorption had been reduced from 198.31 kJ mol À1 for ball milled LiBH 4 to 155.8 kJ mol À1 for 30 mol% h-BN doped LiBH 4 . In addition, the rehydrogenation of the composite is achieved under 400 C and 10 MPa of H 2 . These remarkable results are largely attributed to the lone pair electrons of nitrogen induced destabilization of LiBH 4 and their heterogeneous nucleation.

Fe3O4 nanoclusters highly dispersed on a porous graphene support as an additive for improving the hydrogen storage properties of LiBH4

“…To further study the desorption kinetics of the LiBH 4 –20 wt% y composites (y = Fe 3 O 4 , rGO, and Fe 3 O 4 @rGO), DSC tests at different heating rates were performed to evaluate the activation energy ( E a ) of these composites using Kissinger’s method: 38 …”

Unique Hydrogen Desorption Properties of LiAlH4/h-BN Composites

“…The remarkable hydrogen de/absorption properties were also achieved in the milled LiBH 4 /h-BN composites [18,19]. The 30 mol % h-BN doped LiBH 4 composite started to release hydrogen from 180 • C, which was 100 • C lower than the onset hydrogen desorption temperature of ball-milled LiBH 4 [18]. For the 75 mol % h-BN doped LiBH 4 composite, the on-set desorption temperature of LiBH 4 was reduced to 175 • C and the peak desorption temperature was reduced by 80 • C compared with milled LiBH 4 [19].…”

“…For instance, NH 3 BH 3 /h-BN composite released hydrogen at low temperature with minimum induction time and less exothermicity [17]. The remarkable hydrogen de/absorption properties were also achieved in the milled LiBH 4 /h-BN composites [18,19]. The 30 mol % h-BN doped LiBH 4 composite started to release hydrogen from 180 • C, which was 100 • C lower than the onset hydrogen desorption temperature of ball-milled LiBH 4 [18].…”

Materials Research Directions Towards a Green Hydrogen Economy: A Review

“…It was shown that hexagonal boron nitride (h-BN) additive greatly improves the dehydrogenation of LiBH4. 95 Sodium borohydride (NaBH4) is an excellent hydrogen storage material, but its application is restricted by irreversibility of hydrolysis and high cost of regeneration. To regenerate NaBH4 with high yield and low costs, the hydrolytic product NaBO2 reacts with CO2, forming Na2B4O7•10H2O and Na2CO3, both of which are ball-milled with Mg under ambient conditions to form NaBH4 in high yield (close to 80%).…”