###### Abstract
Therefore, gaining a deep understanding of the dissociative adsorption of hydrogen on metal surfaces and its behavior within the metal is crucial for enhancing the safety and efficiency of pipelines. To address this issue, first principles calculations have played an irreplaceable role in studying the interaction between hydrogen and metals [24; 25]. [PERSON]'s research utilized first principles calculation methods to explore the adsorption mechanisms of hydrogen atoms on the Fe(100) surface, demonstrating how hydrogen atoms dissociate on the metal surface and further interact with the metal [26]. [PERSON] studied the thermodynamics of adsorption and diffusion of hydrogen on transition metals, revealing the influence of different metals on the dissociation of hydrogen molecules [27]. [PERSON] analyzed the impact of elemental segregation on the properties of metal materials by calculating the charge density and state density of grain boundaries [28]. [PERSON] studied the interaction between hydrogen vacancies and grain boundaries in \(\alpha\)-Fe and \(\gamma\)-Fe using first principles, finding that the grain boundary structure has larger vacancies, increasing solubility, with hydrogen having lower mobility within the grain boundaries, acting as traps for hydrogen [29]. Through these methods, researchers can delve into the adsorption mechanisms of hydrogen atoms on different metal surfaces, understand how hydrogen atoms dissociate and interact with metals, and understand how the migration and accumulation of hydrogen within metals affect the mechanical properties of materials. Although existing research has provided us with important insights into the interactions between hydrogen atoms and metals, a deeper understanding of the adsorption and dissociation behaviors of hydrogen on metal surfaces and their impact on hydrogen embrittlement requires comprehensive consideration of the complexity of operational gas pipeline surfaces. This complexity arises not only from changes in microstructure, surface characteristics, and chemical composition due to the aging process of the pipelines but also includes surface by-products caused by environmental factors. Through computer simulation, we can precisely explore the adsorption mechanisms of hydrogen atoms on metal surfaces at the microscopic level. This approach offers new perspectives and strategies to ensure the safety and efficiency of hydrogen transport in natural gas pipelines [30]. This study utilizes first principles calculations to thoroughly investigate the dissociative adsorption process of hydrogen on the Fe(110) surface of X80 pipeline steel, aiming to address the key scientific issues related to the interaction between hydrogen molecules and pipeline steel surfaces. The research focuses on the microscopic mechanisms of hydrogen molecule dissociative adsorption on the Fe(110) surface, involving changes in system energy, bond length adjustments, and alterations in electron and charge distributions, and assesses the spontaneity influenced by environmental temperature and pressure, exploring the role of thermodynamic principles in this process. Through a systematic examination of these issues, this study not only provides a theoretical basis for assessing the feasibility of transporting hydrogen through natural gas pipelines but also offers scientific support for developing safe and efficient hydrogen transport technology strategies. The findings will facilitate the optimization of hydrogen transport and distribution strategies within the natural gas pipeline system, significantly enhancing the performance of pipeline steel and ensuring the stability and safety of the transportation system.