Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
J Chem Phys. 2009 Dec 28;131(24):244510. doi: 10.1063/1.3276282.
In order to accurately estimate the thermodynamic properties of hydrogen clathrate hydrates, we developed a method based on the solid solution theory of van der Waals and Platteeuw. This model allows one to take into account the influence of guest molecules on the host lattice and guest-guest interactions--especially when more than one guest molecule occupies a cage. The free energies, equations of state, and chemical potentials of hydrogen and mixed propane-hydrogen clathrate hydrates of cubic structure II with different cage fillings have been estimated using this approach. Moreover, the proposed theory has been used for construction p-T phase diagrams of hydrogen hydrate and mixed hydrogen-propane hydrates in a wide range of pressures and temperatures. For the systems with well defined interactions the calculated curves of "guest gas-hydrate-ice I(h)" equilibrium agree with the available experimental data. We also believe that the present model allows one not only to calculate the hydrogen storage ability of known hydrogen hydrate but also predict this value for structures that have not yet been realized by experiment.
为了准确估计氢笼形水合物的热力学性质，我们开发了一种基于范德华和普拉特尤（van der Waals and Platteeuw）的固溶理论的方法。该模型可以考虑客体分子对主体晶格和客体-客体相互作用的影响，特别是当一个以上的客体分子占据一个笼时。使用该方法估算了具有不同笼填充的立方结构 II 的氢和混合丙烷-氢笼形水合物的自由能、状态方程和化学势。此外，该理论还用于在较宽的压力和温度范围内构建氢水合物和混合氢-丙烷水合物的 p-T 相图。对于具有明确定义相互作用的体系，计算出的“客体气体-水合物-冰 I(h)”平衡曲线与可用的实验数据相符。我们还认为，该模型不仅可以计算已知氢水合物的储氢能力，还可以预测尚未通过实验实现的结构的储氢能力。
