Tetenoire Auguste, Ehlert Christopher, Juaristi J I, Saalfrank Peter, Alducin M
Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018, Donostia-San Sebastián, Spain.
Heidelberg Institute for Theoretical Studies (HITS gGmbH), Schloss-Wolfsbrunnenweg 35, 69118, Heidelberg, Germany.
J Phys Chem Lett. 2022 Sep 15;13(36):8516-8521. doi: 10.1021/acs.jpclett.2c02327. Epub 2022 Sep 6.
CO oxidation on Ru(0001) is a long-standing example of a reaction that, being thermally forbidden in ultrahigh vacuum, can be activated by femtosecond laser pulses. In spite of its relevance, the precise dynamics of the photoinduced oxidation process as well as the reasons behind the dominant role of the competing CO photodesorption remain unclear. Here we use ab initio molecular dynamics with electronic friction that account for the highly excited and nonequilibrated system created by the laser to investigate both reactions. Our simulations successfully reproduce the main experimental findings: the existence of photoinduced oxidation and desorption, the large desorption to oxidation branching ratio, and the changes in the O K-edge X-ray absorption spectra attributed to the initial stage of the oxidation process. Now, we are able to monitor in detail the ultrafast CO desorption and CO oxidation occurring in the highly excited system and to disentangle what causes the unexpected inertness to the otherwise energetically favored oxidation.
钌（0001）表面的一氧化碳氧化反应是一个长期存在的例子，该反应在超高真空中是热禁阻的，但可以被飞秒激光脉冲激活。尽管其具有重要意义，但光致氧化过程的精确动力学以及竞争性一氧化碳光解吸起主导作用的背后原因仍不清楚。在这里，我们使用考虑了激光产生的高度激发和非平衡系统的含电子摩擦的从头算分子动力学来研究这两个反应。我们的模拟成功再现了主要实验结果：光致氧化和解吸的存在、解吸与氧化的大分支比，以及归因于氧化过程初始阶段的氧 K 边 X 射线吸收光谱的变化。现在，我们能够详细监测高激发系统中发生的超快一氧化碳解吸和一氧化碳氧化，并弄清楚是什么导致了对原本能量上有利的氧化反应出现意外的惰性。
