In a recent issue of Nature Catalysis, Rost et al. directly visualized the step bunching on flame-annealed Pt(111)-vicinal surfaces at high step densities using in situ electrochemical scanning tunneling microscopy (EC-STM). This phenomenon originates from the increased step-step repulsive interaction between closely distanced steps, and the surface-free energy will be lowered when forming bunched steps with wider terraces. This work challenges the common assumption that all stepped surfaces present homogeneously spaced steps of monoatomic height and provides a convincing explanation at atomic level for the anomalous electrochemical behavior of the platinum surface at high step densities, including the activity and potential of zero total charge.

中文翻译：

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使用 EC-STM 可视化 Pt 表面上的阶梯聚束及其在电催化中的影响


在最近一期的《自然催化》杂志上，Rost 等人使用原位电化学扫描隧道显微镜 （EC-STM） 直接可视化了高台阶密度下火焰退火 Pt（111） 附近表面上的台阶聚集。这种现象源于距离较近的台阶之间的台阶-台阶排斥相互作用增加，当形成具有较宽阶地的成束台阶时，无表面能量会降低。这项工作挑战了所有阶梯表面都呈现单原子高度的均匀间隔阶跃的常见假设，并在原子水平上为铂表面在高阶跃密度下的异常电化学行为提供了令人信服的解释，包括零总电荷的活性和电位。