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Abstract: Thermogravimetric analysis of LiAlH4 chemically mixed with different additives is reported for the application of hydrogen storage. Here, we illustrated the dehydrogenation properties of combined LiAlH4/LiNH2 (2:1) mixture and LiAlH4 wet-doped with different transition metals (Sc, Ti, and V) in their chloride forms. Thermal gravimetric analysis of LiAlH4/LiNH2 system released ∼7.9wt.% of hydrogen in three decomposition steps at temperatures between 75 and 280°C under a heating ramp of 5°Cmin−1. The LiAlH4 doped with transition metals showed the decrease of decomposition temperature down to 30–40°C for both 1st and 2nd dehydrogenation steps as compared to as-received LiAlH4. The catalytic activity in lowering the dehydrogenation temperature of LiAlH4 doped with transition metals increases in the order of pure LiAlH4

Abstract: Hydrogen adsorption studies of silver-embedded carbon nanotubes (Ag/CNTs) synthesized by in situ reduction method were performed at 298K and hydrogen equilibrium pressure of 23atm. The saturated reversible hydrogen storage capacity exhibited by silver embedded carbon nanotubes is found to be 0.86wt.% which is nearly 40% more as compared to the hydrogen uptake of purified carbon nanotubes measured under similar experimental conditions. The enhanced hydrogen storage capacity of carbon nanotubes is attributed to the spillover of physisorbed hydrogen from silver nanoparticles. The hydrogen uptake by Ag/CNT samples follows the Henry’s rule, suggesting that there is no significant adsorbate–adsorbate interaction in the low-pressure region. XRD spectrum indicated that 32% increase in particle size was observed in hydrogenated samples as compared to non-hydrogenated samples. [Copyright &y& Elsevier]

Abstract: Hydrogen uptake of Pt–Pd alloy decorated MWCNTs was performed under ambient temperature and moderate pressures. Nanocrystalline alloy is coated on the MWCNTs via thermal vapour deposition (TVD) method. The size of the Pt–Pd alloy decorated by TVD on MWCNTs is 5nm. The maximum reversible hydrogen storage exhibited by nanocomposite, measured at 298K and pressure of 20atm is found to be ∼2.0wt.%, which is nearly 3 times more as compared to pristine CNTs performed under similar experimental conditions. The improvement of hydrogen storage in coated sample as compared to pristine CNTs is due to the spillover of physisorbed hydrogen from the alloy nanoparticles to the CNTs. [Copyright &y& Elsevier]

Abstract: We examined the hydrogen adsorption of palladium-embedded carbon nanotubes (CNTs) under ambient temperature and hydrogen partial pressures: 0.66–2.2MPa. Nano-crystalline palladium is embedded in the MWCNTs via impregnation and in situ reduction reaction. The maximum reversible hydrogen storage exhibited by nanocomposite materials, measured at 298K and 1.6MPa is 0.18wt% which is nearly twice the storage capacity of pristine CNTs. However, the storage capacity of the composite materials is approximately an order less than that of the palladium nanoparticles. The enhanced storage capacity is due to cumulative hydrogen adsorption by CNTs and Pd nanoparticles. We observe no significant difference between the reversible storage capacities of the composites made by two methods, which implies that the storage capacities of the samples essentially depend on the uptake by CNTs. [Copyright &y& Elsevier]