Theoretical Modeling of Phase Diagram of Clathrate Hydrates toward Hydrogen Storage Applications

Original approach accounting for multiple cage occupancy, host lattice relaxation, and the description of the quantum nature of guest behavior has been used for estimation the thermodynamic properties of pure hydrogen and binary X+H-2 hydrates with the possibility of multiple filling of cavities by guest molecules. The thermodynamic conditions of hydrate formation at equilibrium with ice phase have been determined. The hydrogen storage content in hydrates is estimated in wide range of p-T regions. This approach can be useful for understanding the thermodynamic properties of the binary hydrate and it can support the experimental exploration of novel hydrogen storage materials based on clathrate hydrates. The method is general and can apply to the various non-stoichiometric inclusion compounds with weak guest-host and guest-guest interactions.