Abstract:

Under the pressing “dual-carbon” goals and the green transition of energy structures, hydrogen energy has garnered widespread attention due to its abundant sources, high combustion calorific value, green and low-carbon properties, and broad applicability. As an emerging solid-state hydrogen storage technology, hydrogen storage via hydrates demonstrates significant advantages in safety and high storage density, showing immense developmental prospects and application value. However, the advancement of hydrate-based hydrogen storage technology is currently hindered by critical challenges, including stringent formation conditions, slow growth rates, and unstable hydrogen storage density. The root cause of these bottlenecks lies in the unclear molecular dynamics behaviors and mechanisms governing the interactions among hydrogen molecules, water molecules, and promoter molecules during the hydrogen storage process. To address these issues, this study focuses on the molecular dynamics behaviors and mechanisms in hydrogen storage hydrates. Specifically, it comprehensively reviews the kinetic growth mechanisms of hydrogen hydrates under the influence of promoters, elucidating the stable filling of hydrate cages and the inter-cage diffusion behavior of molecules within promoter-enhanced systems. The findings provide molecular-level insights to support the refinement of thermodynamic and kinetic theoretical frameworks for hydrogen hydrate formation facilitated by promoters. This research aims to advance the efficient hydrogen storage in cage-like hydrates with promoter assistance, thereby accelerating the development and practical application of hydrate-based hydrogen storage technologies.

Key words: hydrogen hydrate, molecular dynamics behavior, formation mechanism, molecular diffusion, stability of cavity structure, promoter

摘要：

在“双碳”目标迫近及能源结构绿色转型的背景下，氢能因其来源丰富、燃烧热值高、绿色低碳及应用广泛的特点而受到广泛关注。水合物储氢作为一种新兴的固态储氢技术，表现出储氢安全性高且储氢密度大的特点，具有巨大的发展前景及应用价值。然而，目前水合物储氢技术的发展受困于氢气水合物形成条件严苛、生长速率低及储氢密度不稳定等问题。上述问题存在的根本原因在于水合物储氢过程中氢分子、水分子和促进剂分子间的相关动力学行为及机制尚不明确。基于此，本文以水合物储氢过程的分子动力学行为及机制为研究对象，阐述了促进剂作用下氢气水合物的动力学生长机制，研究了促进剂作用下氢气水合物笼形孔穴的稳定填充以及水合物中的分子笼间扩散行为。本文研究结果可为促进剂作用下氢气水合物形成热力学及动力学理论体系的完善提供分子层面的成果支持，助力水合物储氢技术的发展与应用。

关键词: 水合物储氢, 分子动力学, 形成机理, 分子扩散, 孔穴结构稳定性, 促进剂