The role of sticking and reaction probabilities in hot-atom mediated abstraction reactions of D on metal surfaces by gaseous H atoms
The role of sticking and reaction probabilities in hot-atom mediated abstraction reactions of D on metal surfaces by gaseous H atoms
复制标题
气态氢原子在金属表面热原子介导的 D 抽象反应中粘附和反应概率的作用
DOI：
10.1063/1.477007
复制
发表时间：
1998
影响因子：
4.4
通讯作者：
J. Küppers
中科院分区：
文献类型：
--
作者：
T. Kammler;S. Wehner;J. Küppers
最近的实验上的抽象D吸附在金属表面上的气态氢原子揭示了HD形成的动力学，这是不兼容的操作的Eley-Rideal（ER）机制。此外，在提取过程中观察到homomethyl产物，这是通过ER反应方案预期不到的。因此，有人建议，热原子（HA）机制是更合适的解释测得的动力学和产品。随机游走计算的抽象动力学模型的基础上，完全依赖于基本的反应步骤，这是HA介导的过程。在这个模型中，两个变量的比例，热原子粘在空站点PS和热原子反应与吸附物种PR的概率，被发现控制HD和D2形成的动力学。通过对ps/pr的简单合理的假设，再现了Ni（100），Pt（111）和Cu（111）表面动力学数据的基本特征。
Recent experiments on the abstraction of D adsorbed on metal surfaces with gaseous hydrogen atoms revealed a kinetics of HD formation which is not compatible with the operation of Eley–Rideal (ER) mechanisms. Furthermore, homonuclear products were observed during abstraction, which are not expected through an ER reaction scheme. It was therefore suggested that hot-atom (HA) mechanisms are more appropriate to explain the measured kinetics and products. Random walk calculations of the abstraction kinetics are presented based on a model which exclusively relies on elementary reaction steps which are HA mediated processes. Within this model, the ratio of two variables, the probabilities for hot-atom sticking at empty sites ps and hot-atom reaction with adsorbed species pr, was found to control the kinetics of HD and D2 formation. The essential features of measured kinetic data at Ni(100), Pt(111), and Cu(111) surfaces were reproduced by simple and reasonable assumptions on ps/pr.