Liu Jinwen, Hagopian Arthur, McCrum Ian T, Doblhoff-Dier Katharina, Koper Marc T M
Leiden Institute of Chemistry, Leiden University, Leiden 2333 CC, The Netherlands.
Department of Chemical and Biomolecular Engineering, Clarkson University, Potsdam, New York 13699, United States.
J Phys Chem C Nanomater Interfaces. 2024 Aug 29;128(36):15019-15028. doi: 10.1021/acs.jpcc.4c05193. eCollection 2024 Sep 12.
Hydrogen adsorption on platinum (Pt) single-crystal electrodes has been studied intensively in both experiments and computations. Yet, the precise origin and nature of the repulsive interactions observed between hydrogen adsorbates (H) have remained elusive. Here, we use first-principles density functional theory calculations to investigate in detail the interactions between H on Pt(111), Pt(100), and Pt(110) surfaces. The repulsive interaction between H on Pt(111) is deconvoluted into three different physical contributions, namely, (i) electrostatic interactions, (ii) surface distortion effect, and (iii) surface coordination effect. The long-range electrostatic interaction, which is generally considered the most important source of repulsive interactions in surface adsorption, was found to contribute less than 30% of the overall repulsive interaction. The remaining >70% arises from the other two contributions, underscoring the critical influence of surface-mediated interactions on the adsorption process. Surface distortion and coordination effects are found to strongly depend on the coverage and adsorption geometry: the effect of surface distortion dominates when adsorbates reside two or more Pt atoms apart; the effect of surface coordination dominates if hydrogen is adsorbed on neighboring adsorption sites. The above effects are considerably less pronounced on Pt(100) and Pt(110), therefore resulting in weaker interactions between H on these two surfaces. Overall, the study highlights the relevance of surface-mediated effects on adsorbate-adsorbate interactions, such as the often-overlooked surface distortion. The effect of these interactions on the hotly debated adsorption site for the adsorbed hydrogen intermediate in the hydrogen evolution reaction is also discussed.
在实验和计算方面，人们对氢在铂（Pt）单晶电极上的吸附进行了深入研究。然而，氢吸附质（H）之间观察到的排斥相互作用的确切起源和本质仍然难以捉摸。在这里，我们使用第一性原理密度泛函理论计算，详细研究了H在Pt(111)、Pt(100)和Pt(110)表面之间的相互作用。Pt(111)上H之间的排斥相互作用被分解为三种不同的物理贡献，即：（i）静电相互作用，（ii）表面畸变效应，以及（iii）表面配位效应。通常被认为是表面吸附中排斥相互作用最重要来源的长程静电相互作用，其对总排斥相互作用的贡献不到30%。其余>70%来自其他两种贡献，这突出了表面介导的相互作用对吸附过程的关键影响。发现表面畸变和配位效应强烈依赖于覆盖度和吸附几何结构：当吸附质相距两个或更多Pt原子时，表面畸变效应占主导；如果氢吸附在相邻的吸附位点上，则表面配位效应占主导。上述效应在Pt(100)和Pt(110)上不太明显，因此导致这两个表面上H之间的相互作用较弱。总体而言，该研究突出了表面介导效应与吸附质 - 吸附质相互作用的相关性，例如常常被忽视的表面畸变。还讨论了这些相互作用对析氢反应中吸附氢中间体备受争议的吸附位点的影响。
