TY - JOUR

T1 - Enhanced dehydrogenation and regeneration behavior of LiBH4–LiAlH4–MgCl2 in nanoporous carbons

AU - Hsu, C.-Y.

AU - Kostoglou, Nikolaos

AU - Mitterer, Christian

AU - Rebholz, Claus

AU - Chang, Chung-Kai

AU - Chuang, Yu-Chun

AU - Wang, Cheng-Yu

N1 - Publisher Copyright: © 2025 Hydrogen Energy Publications LLC

PY - 2025/2/5

Y1 - 2025/2/5

N2 - With high hydrogen capacity, lithium borohydride (LiBH 4, LBH) is considered as a promising hydrogen storage material. However, high dehydrogenation temperature (460 °C) and critical rehydrogenation conditions (155 bar H 2 at 600 °C), hindered by the stable Li 2B 12H 12, downgrade the LBH application in hydrogen storage. In this research, we investigated the nanoconfinement effect of LBH with lithium aluminum hydride (LiAlH 4, LAH, also called lithium alanate) and magnesium chloride (MgCl 2), forming a ternary system LiBH 4–LiAlH 4–MgCl 2 (borohydride, alanate, and magnesium chloride; BAM) in different porous carbon supports. BAM confined in activated carbon (BAM@AC) showed the lowest peak dehydrogenation temperature at 227 °C, with a 98.6% hydrogen generation yield. The activation energy of LBH decomposition decreased tremendously from 146 to 59 kJ/mol in BAM@AC with reaction path modification. For rehydrogenation, 93.71% of LBH was regenerated in BAM@AC at 350 °C under 30 bar H 2. The improved LBH rehydrogenation is due to the formation of MgAlB 4 after BAM thermolysis, which represented the manipulation of the reaction route and the prohibition of Li 2B 12H 12 formation. The much lower dehydrogenation temperatures and mild regeneration conditions in lithium borohydride show a promising perspective in the future development of complex metal hydrides in hydrogen storage.

AB - With high hydrogen capacity, lithium borohydride (LiBH 4, LBH) is considered as a promising hydrogen storage material. However, high dehydrogenation temperature (460 °C) and critical rehydrogenation conditions (155 bar H 2 at 600 °C), hindered by the stable Li 2B 12H 12, downgrade the LBH application in hydrogen storage. In this research, we investigated the nanoconfinement effect of LBH with lithium aluminum hydride (LiAlH 4, LAH, also called lithium alanate) and magnesium chloride (MgCl 2), forming a ternary system LiBH 4–LiAlH 4–MgCl 2 (borohydride, alanate, and magnesium chloride; BAM) in different porous carbon supports. BAM confined in activated carbon (BAM@AC) showed the lowest peak dehydrogenation temperature at 227 °C, with a 98.6% hydrogen generation yield. The activation energy of LBH decomposition decreased tremendously from 146 to 59 kJ/mol in BAM@AC with reaction path modification. For rehydrogenation, 93.71% of LBH was regenerated in BAM@AC at 350 °C under 30 bar H 2. The improved LBH rehydrogenation is due to the formation of MgAlB 4 after BAM thermolysis, which represented the manipulation of the reaction route and the prohibition of Li 2B 12H 12 formation. The much lower dehydrogenation temperatures and mild regeneration conditions in lithium borohydride show a promising perspective in the future development of complex metal hydrides in hydrogen storage.

KW - Dehydrogenation

KW - Lithium borohydride

KW - Nanoconfinement

KW - Nanoporous carbons

KW - Regeneration

UR - http://www.scopus.com/inward/record.url?scp=85216901447&partnerID=8YFLogxK

U2 - 10.1016/j.ijhydene.2025.01.377

DO - 10.1016/j.ijhydene.2025.01.377

M3 - Article

VL - 106.2025

SP - 712

EP - 722

JO - International Journal of Hydrogen Energy

JF - International Journal of Hydrogen Energy

SN - 0360-3199

IS - 6 March

ER -