Improvement of dehydrogenation kinetics of LiBH4 dispersed on modified multi-walled carbon nanotubes.

The dehydrogenation kinetics of LiBH4 dispersed on multi-walled carbon nanotubes (MWCNTs) by the solvent infiltration technique has been studied. Commercial MWCNTs were ball-milled for different milling times in order to increase the specific surface area (SSA) as measured by the BET technique. Thermal programmed desorption measurements have been performed using a Sievert's apparatus on samples with different SSA of MWCNTs and different LiBH4 to MWCNT ratio. Pressure composition isotherms (PCI) have been obtained at different temperatures in order to estimate the ΔH and ΔS of dehydrogenation. It has been observed that the dispersion of LiBH4 on MWCNTs leads to a lower dehydrogenation temperature compared to pure LiBH4. Moreover, the dehydrogenation temperature further decreases with increasing MWCNT surface area. An interpretation of the kinetic effect is proposed.