Following the microscopic pathway to adsorption through chemisorption and physisorption wells
Following the microscopic pathway to adsorption through chemisorption and physisorption wells
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DOI：
10.1126/science.abc9581
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发表时间：
2020-09-18
期刊：
影响因子：
56.9
通讯作者：
Wodtke, Alec M.
中科院分区：
文献类型：
--
作者：
Borodin, Dmitriy;Rahinov, Igor;Wodtke, Alec M.
吸附过程涉及分子在固体表面发生碰撞，并通过动态途径达到平衡从而失去其入射能量。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，我们介绍了一些实验，这些实验揭示了一个定量的能量态势以及在一个典型系统中分子与表面达到平衡的微观途径：一氧化碳在金（111）表面的吸附。尽管最低能量状态是物理吸附，但用高能分子束注入的气相分子最初是被捕获到一个亚稳态的化学吸附状态。化学吸附态随后的热衰变使分子达到物理吸附的最低能量状态。我们通过细致平衡发现，在所有温度下，热吸附到两种结合状态都很重要。
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.