Enhanced dehydrogenation kinetics of LiBH4 catalyzed by Ti/V/Li3BO3 hetero-ensembles derived from Ti2VC2 MXene

To address the sluggish dehydrogenation kinetics and high operating temperatures of LiBH 4 , Ti 2 VC 2 MXene was incorporated with LiBH 4 to modify its dehydrogenation performance. With 40 wt% Ti 2 VC 2 MXene additive, the onset dehydrogenation temperature of LiBH 4 is reduced to 98.31 °C, while the peak hydrogen release occurs at 332.86 °C. Isothermal dehydrogenation measurements demonstrate that the composite rapidly desorbs 9.50 wt% H 2 within 40 min at 325 °C, 10.67 times faster than that of LiBH 4 . Furthermore, the addition of 40 wt% Ti 2 VC 2 MXene effectively lowers the activation energies for the dehydrogenation to 104.76 and 112.99 kJ mol⁻ 1 , respectively. Mechanism studies reveal that the enhanced dehydrogenation performance originates from the in-situ formation of catalytic active species, including Ti 0 , V 0 and Li 3 BO 3 , promoting the cleavage of ionic and covalent bonds in LiBH 4 . Simultaneously, the multiphase Ti/V/Li 3 BO 3 hetero-ensembles create abundant interfacial boundaries, serving as efficient pathways for hydrogen diffusion and accelerating the dehydrogenation kinetics.