目前，天然气水合物成藏和开采是新能源开发应用的热点，但海域沉积物中天然气水合物的形成/分解特性，及盐离子对水合物稳定性的影响等关键问题亟待解决。利用天然气水合物原位取样技术对甲烷水合物在含盐多孔介质中生成和分解过程进行原位扫描电镜(Scanning Electron Microscopy, SEM)测试和能谱分析(Energy Dispersive Spectrometry, EDS)，系统研究了含0.5 mol/L NaCl溶液的蒙脱石中甲烷水合物生成、分解过程中形貌的变化及离子分布特征。研究发现水合物生成和分解过程元素分布发生明显改变，水合物生成的排盐效应使得NaCl在水合物颗粒与颗粒交结处以水合盐离子的形成存在，并且Na+和Cl-在蒙脱石表面分层排布。水合物生成后蒙脱石表面呈独立颗粒状，水合物分解后蒙脱石表面凹陷并形成微小的气体通道，并且水合物分解后蒙脱石的骨架堆积结构发生改变。研究得出水合物成核、生长、分解过程均在特定基元颗粒间是独立进行的，并且生长与分解过程与水合物晶胞结构有关。

Natural gas hydrate accumulation and exploitation is a research focus on the development and application of new energy. However, a group of key issues involving the formation and dissociation characteristics of natural gas hydrate in marine sediments and the effect of salt ions on the hydrate stability remains to be solved. Based on the in situ sampling technique, the formation and dissociation processes of methane hydrate in montmorillonite contained saline solution was explored by in situ scanning electron microscopy and energy dispersive spectrometry. Furthermore, the morphology and ion distribution of methane hydrate during the formation and dissociation processes in montmorillonite adsorbing 0.5 mol/L NaCl solution were systematically analyzed. The results showed that the element distribution changed obviously during the hydrate formation and dissociation processes. NaCl was located on the boundary between hydrate granules caused by the salt-removing effect of hydrate formation and existed as the form of hydrated salt ions. Na+ and Cl- were distributed on the surface of montmorillonite as different layers. The surfaces of montmorillonite present the structure of independent granular while methane hydrate was formed. After the hydrate dissociation, the surfaces of montmorillonite sunk and formed some tiny gas channels. At the same time, the packing structures of montmorillonite were changed. The research demonstrated that the processes of hydrate nucleation, growth, and decomposition took place independently on the special unit between particles. Those processes had a closed relationship with the unit cell structure of hydrate.