Reversible Storage of Molecular Hydrogen by Sorption into Multilayered TiO2 Nanotubes

The sorption of hydrogen between the layers of the multilayered wall of nanotubular TiO2 was studied in the temp. range of -195 to 200 DegC and at pressures of 0 to 6 bar. Hydrogen can intercalate between layers in the walls of TiO2 nanotubes forming host-guest compds. TiO2.xH2, where x ? 1.5 and decreases at higher temps. The rate of hydrogen incorporation increases with temp. and the characteristic time for hydrogen sorption in TiO2 nanotubes is several hours at 100 DegC. The rate of intercalate formation is limited by the diffusion of mol. hydrogen inside the multilayered walls of the TiO2 nanotube. 1H NMR-MAS and XRD data confirm the incorporation of hydrogen between the layers in the walls of TiO2 nanotubes. The nature and possible applications of the obsd. intercalates are considered. [on SciFinder (R)]