Methane clathrates are widespread on the ocean floor of the Earth. A better understanding of methane clathrate formation has important implications for natural-gas exploitation, storage, and transportation. A key step toward understanding clathrate formation is hydrate nucleation, which has been suggested to involve multiple evolution pathways. Herein, a unique nucleation/growth pathway for methane clathrate formation has been identified by analyzing the trajectories of large-scale molecular dynamics (MD) simulations. In particular, ternary water-ring aggregations (TWRAs) have been identified as fundamental structures for characterizing the nucleation pathway. Based on this nucleation pathway, the critical nucleus size and nucleation timescale can be quantitatively determined. Specifically, a methane hydration layer compression/shedding process is observed to be the critical step in (and driving) the nucleation/growth pathway, which is manifested through overlapping/compression of the surrounding hydration layers of the methane molecules, followed by detachment (shedding) of the hydration layer. As such, an effective way to control methane hydrate nucleation is to alter the hydration layer compression/shedding process during the course of nucleation.

甲烷包合物广泛存在于地球海底。更好地了解甲烷笼形物的形成对于天然气的开采、储存和运输具有重要意义。了解笼形物形成的关键一步是水合物成核，这被认为涉及多种演化途径。在此，通过分析大规模分子动力学（MD）模拟的轨迹，确定了甲烷笼形物形成的独特成核/生长途径。特别是，三元水环聚集体（TWRA）已被确定为表征成核途径的基本结构。基于该成核途径，可以定量确定临界核尺寸和成核时间尺度。具体来说，甲烷水化层压缩/脱落过程被观察到是（并驱动）成核/生长路径的关键步骤，这通过甲烷分子周围水化层的重叠/压缩以及随后的分离（脱落）来体现。 ）的水化层。因此，控制甲烷水合物成核的有效方法是改变成核过程中水化层的压缩/脱落过程。