[1][2] A recent review that accounts the state-of-the-art and future prospects and challenges of hydrogen storage as clathrate hydrates is reported by Veluswamy et al.
It takes about 30 minutes to form, so this method is impractical for rapid manufacture.
Below 120K the molecules stop racing around the cage, and below 50K are locked into a fixed position.
[6] Under even higher pressures (over 38 GPa) there is a prediction of the existence of a clathrate with a cubic structure and a 1:2 ratio: 2H2•H2O.
[7] More complex clathrates can occur with hydrogen, water and other molecules such as methane,[8] and tetrahydrofuran.