Institute for Physical Chemistry, Georg-August University of Göttingen, Tammannstraße 6, 37077 Göttingen, Germany.
Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077 Göttingen, Germany.
Science. 2020 Sep 18;369(6510):1461-1465. doi: 10.1126/science.abc9581.
Adsorption involves molecules colliding at the surface of a solid and losing their incidence energy by traversing a dynamical pathway to equilibrium. The interactions responsible for energy loss generally include both chemical bond formation (chemisorption) and nonbonding interactions (physisorption). In this work, we present experiments that revealed a quantitative energy landscape and the microscopic pathways underlying a molecule's equilibration with a surface in a prototypical system: CO adsorption on Au(111). Although the minimum energy state was physisorbed, initial capture of the gas-phase molecule, dosed with an energetic molecular beam, was into a metastable chemisorption state. Subsequent thermal decay of the chemisorbed state led molecules to the physisorption minimum. We found, through detailed balance, that thermal adsorption into both binding states was important at all temperatures.
吸附涉及分子在固体表面的碰撞，并通过遍历动态途径到达平衡来失去其入射能量。导致能量损失的相互作用通常包括化学键形成（化学吸附）和非键相互作用（物理吸附）。在这项工作中，我们展示了实验结果，揭示了一个定量的能量景观和分子与表面平衡的微观途径，这是一个典型的系统：CO 在 Au(111)上的吸附。尽管最低能量状态是物理吸附，但用高能分子束注入气相分子的初始捕获是进入亚稳化学吸附状态。随后化学吸附态的热衰减导致分子进入物理吸附的最低能量状态。我们通过详细平衡发现，在所有温度下，热吸附到两种结合状态都是重要的。
