Due to the hybrid effect of physical adsorption and hydration, methane storage capacity in pre-adsorbed water-activated carbon (PW-AC) under hydrate favorable conditions is impressive, and fast nucleation and growth kinetics are also anticipated. Those fantastic natures suggest the PW-AC-based hydrates to be a promising alternative for methane storage and transportation. However, hydrate formation refers to multiscale processes, the nucleation kinetics at molecule scale give rise to macrohydrate formation, and the presence of activated carbon (AC) causes this to be more complicated. Although adequate nucleation sites induced by abundant specific surface area and pore texture were reported to correspond to fast formation kinetics at macroperspective, the micronature behind that is still ambiguous. Here, we evaluated how methane would be adsorbed on PW-AC under hydrate favorable conditions to improve the understanding of hydrate fast nucleation and growth kinetics. Microbulges on AC surface were confirmed to provide numerous nucleation sites, suggesting the contribution of abundant specific surface area of AC to fast hydrate nucleation and growth kinetics. In addition, two-way convection of water and methane molecules in micropores induced by methane physical adsorption further increases gas–liquid contact at molecular scale, which may constitute the nature of confinement effect of nanopore space.

由于物理吸附和水合作用的混合效应，在水合物有利条件下，预吸附的水活性炭（PW-AC）中的甲烷存储能力令人印象深刻，并且还有望实现快速成核和生长动力学。那些奇妙的性质表明，基于PW-AC的水合物是甲烷存储和运输的有希望的替代品。但是，水合物的形成是指多尺度过程，分子尺度上的成核动力学会导致大水合物的形成，而活性炭（AC）的存在则使其更加复杂。尽管据报道，由大的比表面积和孔结构诱导的足够的成核位点对应于宏观上的快速形成动力学，但其背后的微观性质仍然是模棱两可的。这里，我们评估了在水合物有利条件下甲烷将如何吸附在PW-AC上，以增进对水合物快速成核和生长动力学的理解。确认到AC表面的微凸起可提供许多成核位置，表明AC丰富的比表面积对快速水合物成核和生长动力学的贡献。此外，甲烷物理吸附引起的微孔中水和甲烷分子的对流进一步增加了分子尺度上的气液接触，这可能构成了纳米孔空间的封闭效应。提示AC丰富的比表面积对快速水合物成核和生长动力学的贡献。此外，甲烷物理吸附引起的微孔中水和甲烷分子的对流进一步增加了分子尺度上的气液接触，这可能构成了纳米孔空间的封闭效应。提示AC丰富的比表面积对快速水合物成核和生长动力学的贡献。此外，甲烷物理吸附引起的微孔中水和甲烷分子的对流进一步增加了分子尺度上的气液接触，这可能构成了纳米孔空间的封闭效应。