Rotational Dynamics of Desorption: Methane and Ethane at Stepped and Kinked Platinum Surfaces
Rotational Dynamics of Desorption: Methane and Ethane at Stepped and Kinked Platinum Surfaces
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DOI：
10.1021/acs.jpcc.1c09120
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发表时间：
2021-12-17
影响因子：
3.7
通讯作者：
Jenkins, Stephen J.
中科院分区：
文献类型：
--
作者：
Matysik, Sabine C.;Wales, David J.;Jenkins, Stephen J.
在研究表面与吸附物之间的相互作用时，分子的转动常被忽略。在这项工作中，我们仔细分析了甲烷和乙烷分子从两个不同的铂表面解吸的第一性原理分子动力学模拟的旋转动力学。相对于其旋转对称性，甲烷，吸附动力学的基准系统，构成一个球形的顶部和乙烷是一个对称的顶部。我们集中在非手性Pt{110}-（1x 2）表面，它表现出镜像对称性和阶梯几何形状，并在手性Pt{531}表面，它表现出扭结网站和缺乏反射对称性。对于甲烷，两个表面中的任何一个都不会引起强的或定向的角动量，而对于乙烷，我们发现与Pt{110}-（1x 2）相比，从Pt{531}解吸时分子旋转的方向性增加。微观可逆性的原理意味着这样的结果（在时间反演中）也将与吸附过程相关，因此吸附过程对进入分子的初始旋转状态敏感。
When the interactions between surfaces and adsorbates are studied, molecular rotations are often neglected. In this work, we carefully analyze the rotational dynamics of methane and ethane molecules desorbing from two different platinum surfaces by means of first-principles molecular dynamics simulations. With respect to its rotational symmetry, methane, a benchmark system for adsorption dynamics, constitutes a spherical top and ethane is a symmetric top. We focus on the achiral Pt{110}-(1x2) surface, which exhibits both mirror symmetry and a stepped geometry, and on the chiral Pt{531} surface, which exhibits kink sites and lacks reflection symmetry. For methane, neither a strong nor directed angular momentum is induced by either of the two surfaces, whereas for ethane we find an increased directionality for the molecular rotation upon desorption from Pt{531} compared to Pt{110}-(1x2). The principle of microscopic reversibility implies that such results (in time reversal) will also be relevant to the process of adsorption, which would therefore be sensitive to the initial rotational state of incoming molecules.