Buga Mihaela, Murariu Teodora, Pioraş-Ţimbolmaş Larisa-Milena, Tripon Carmen, Buimaga-Iarinca Luiza, Morari Cristian
National Research and Development Institute for Cryogenic and Isotopic Technologies Rm.Valcea ICSI ENERGY, 4 Uzinei Str., 240050, Rm.Valcea, Romania.
National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293, Cluj Napoca, Romania.
Sci Rep. 2025 Aug 13;15(1):29770. doi: 10.1038/s41598-025-15064-y.
The mechanism governing hydrogen diffusion on Zn surfaces plays a crucial role in the hydrogen evolution reaction (HER). This reaction is vital for various technological applications, particularly its influence on the cycling stability of aqueous Zn-ion batteries. However, the fundamental relationship between hydrogen diffusion, Zn surface properties, and HER remains unclear. In this study, we investigate the dynamics of hydrogen on Zn surfaces using density functional theory and ab initio molecular dynamics. Molecular dynamics data allow us to estimate the vibrational density of states of adsorbed hydrogen and to calculate the diffusion coefficients. Vibrational data indicate that the vibrational motion parallel to the surface of the hydrogen atom has a similar frequency to that of the surface phonons, suggesting the role of vibrations in the diffusion process; moreover, we calculate the diffusion coefficient on top of a frozen surface and get values that are several orders of magnitude lower than those obtained in the presence of surface phonons, i.e. [Formula: see text] [Formula: see text].
锌表面氢扩散的控制机制在析氢反应(HER)中起着关键作用。该反应对各种技术应用至关重要,尤其是对水系锌离子电池循环稳定性的影响。然而,氢扩散、锌表面性质和析氢反应之间的基本关系仍不清楚。在本研究中,我们使用密度泛函理论和从头算分子动力学研究了锌表面氢的动力学。分子动力学数据使我们能够估计吸附氢的振动态密度并计算扩散系数。振动数据表明,氢原子平行于表面的振动运动频率与表面声子相似,这表明振动在扩散过程中起作用;此外,我们计算了冻结表面上的扩散系数,得到的值比存在表面声子时获得的值低几个数量级,即[公式:见正文][公式:见正文]。