Guo Yuzhen, McKenzie David R
Materials Physics Laboratory, School of Physics, The University of Sydney, Physics Rd, Camperdown, Sydney, NSW, 2006, Australia.
Commun Chem. 2025 Apr 1;8(1):97. doi: 10.1038/s42004-025-01489-z.
The reason for the abundance of molecular hydrogen (H) in space remains unresolved. Here we study collision dynamics under spacelike conditions to test H formation mechanisms where carbonaceous dust grains may have a catalytic role. Density functional theory molecular dynamics simulates atomic hydrogen capture and H formation on the surface of buckminsterfullerene as a carbonaceous cosmic dust model. Maximally localized Wannier functions are applied to examine the electronic bonding during transition states. The fullerene surface is shown to be effective at warm (50K) and low (10K) temperatures in achieving atomic H chemisorption, potentially explaining the observed broad temperature range for efficient H formation. We revise the Eley-Rideal mechanism and propose that both it and the Langmuir-Hinshelwood mechanism, induced by thermal hopping, contribute to bursts of H formation during energetic events. Additionally, we show how fullerene maintains the abundance of H in space by selectively preventing H molecules from capture.
太空中分子氢（H）大量存在的原因仍未得到解决。在此，我们研究类空条件下的碰撞动力学，以测试含碳尘埃颗粒可能具有催化作用的氢形成机制。密度泛函理论分子动力学模拟了作为含碳宇宙尘埃模型的巴基球表面的原子氢捕获和氢形成过程。应用最大局域化万尼尔函数来研究过渡态期间的电子键合。结果表明，在温暖（50K）和低温（10K）条件下，富勒烯表面在实现原子氢化学吸附方面是有效的，这可能解释了观察到的高效氢形成的较宽温度范围。我们修正了埃利 - 里德机理，并提出它以及由热跳跃引发的朗缪尔 - 欣谢尔伍德机理，都有助于在高能事件期间氢形成的爆发。此外，我们展示了富勒烯如何通过选择性地阻止氢分子被捕获来维持太空中氢的丰度。
