Hansen Martin Hangaard, Nilsson Anders, Rossmeisl Jan
Nano Science Center, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark.
Department of Physics, AlbaNova University Center, Stockholm University, S-10691 Stockholm, Sweden.
Phys Chem Chem Phys. 2017 Aug 30;19(34):23505-23514. doi: 10.1039/c7cp03576d.
We present atomic-scale structures of the Pt(111)/water interface, by calculating distributions of atomic distances as functions of pH. The structure of the Pt(111)/water interface is a particularly interesting model system in electro-catalysis for proton exchange reactions, especially the oxygen reduction reaction in polymer electrolyte membrane fuel cells. Further insight into such reactions requires accurate simulations of the electrolyte structure in the interface. The study displays many interesting details in the behaviour of the electrolyte structure, e.g. that the electrolyte structure average responds to the presence of protons by a H-down water orientation and that hexagonal adsorbed water layers are present only when they are anchored at the surface by HO*. New adsorbate configurations were also found at 5/12 ML coverage of HO*, suggesting an explanation for reported cyclic voltammetry experiments. The present study is a step towards a more complete understanding of the structure of the electrochemical interface on the atomic scale.
我们通过计算原子距离分布作为pH值的函数，展示了Pt(111)/水界面的原子尺度结构。Pt(111)/水界面的结构是电催化中质子交换反应，特别是聚合物电解质膜燃料电池中氧还原反应的一个特别有趣的模型系统。对这类反应的进一步深入了解需要对界面中的电解质结构进行精确模拟。该研究揭示了电解质结构行为中的许多有趣细节，例如电解质结构平均值通过H向下的水取向对质子的存在做出响应，并且只有当六边形吸附水层通过HO锚定在表面时才会出现。在HO的5/12 ML覆盖度下还发现了新的吸附物构型，这为报道的循环伏安法实验提供了解释。本研究朝着在原子尺度上更全面地理解电化学界面的结构迈出了一步。
