In our earlier work we showed that tetrahydrofuran (THF) is able to stabilize structure sII of hydrogen clathrate hydrate at ambient conditions [1]. This finding was recognized as a potential storage material for hydrogen. Recent research established that cyclopentane (CP) is an even better promoter for structure sII than THF. At a temperature of 281 K an equilibrium pressure as low as of 2 MPa turned out to be feasible. Neutron scattering experiments are in progress to determine the hydrogen storage capacity of this material. Furthermore, it was discovered for the first time that molecules like methylcyclohexane (MCH) and others are able to stabilize structure sH in presence of hydrogen [2]. The latter structure is supposed to have a higher storage capacity for hydrogen than structure sII. Finally, we studied the kinetics of hydrogen uptake and release in structure sII. It was found that both processes are completely reversible [3]. A spray technique proved that the solid material easily can be produced in large amounts. This presentation will report on the three novel findings as pointed out above.

[1] Florusse et al., Science 306 (2004) 469.
[2] Duarte, et al; J. Phys. Chem. B, in press.
[3] Duarte et al. J. Phys. Chem. B, submitted.

Acknowledgement

Financial support from ACTS / NWO (Praktische Verkenning) and EC FP6 (NESSHY contract no. 518271) are greatfully acknowledged.