CO 在 Pt(111)上氧化的空间位阻效应。

Steric effect in CO oxidation on Pt(111).

机构信息

National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.

出版信息

J Chem Phys. 2017 Nov 21;147(19):194705. doi: 10.1063/1.5001683.

Abstract

We present experimental evidence showing that the rate of CO oxidation on Pt(111) depends strongly on the geometry of an incident O molecule. The O sticking probability and the CO production rate on CO-covered Pt(111) surfaces during the alignment-controlled O beam irradiation were simultaneously monitored at a surface temperature of 330 K. The results indicate that, at the translational energy of 0.1-0.2 eV and at the CO coverage of <0.4 monolayers, both O adsorption and CO oxidation proceed exclusively when the O molecular axis is nearly parallel to the surface.

摘要

我们提出了实验证据，表明 CO 在 Pt(111)上的氧化速率强烈依赖于入射 O 分子的几何形状。在表面温度为 330 K 时，我们在 CO 覆盖的 Pt(111)表面上通过控制 O 束的对准，同时监测了 O 吸附的 sticking 概率和 CO 生成速率。结果表明，在 0.1-0.2 eV 的平移能量和 <0.4 单层的 CO 覆盖度下，只有当 O 分子轴几乎平行于表面时，O 吸附和 CO 氧化才会同时进行。