In Situ Oxidation Study of Pt(110) and Its Interaction with CO
In Situ Oxidation Study of Pt(110) and Its Interaction with CO
复制标题
Pt(110)的原位氧化及其与CO的相互作用研究
DOI：
10.1021/ja207261s
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发表时间：
2011-12-21
影响因子：
15
通讯作者：
Liu, Zhi
中科院分区：
文献类型：
--
作者：
Butcher, Derek R.;Grass, Michael E.;Liu, Zhi
在O-2暴露的Pt（110）中观察到许多有趣的结构。这些结构，沿着其对CO的稳定性和反应性，提供了对开放Pt表面上的催化过程的见解，其与Pt纳米颗粒催化剂具有相似性。在这项研究中，我们提出的结果，从环境压力的X射线光电子能谱，高压扫描隧道显微镜，和密度泛函理论计算。在低氧压下，在Pt（110）表面上仅观察到化学吸附的氧。在较高的压力（0.5托的O-2），纳米级的多层α-PtO 2的表面氧化物形成的岛屿沿着与化学吸附的氧。在270 K时，CO的存在使化学吸附氧和表面氧化物同时消失，表面氧化物的消失速率与化学吸附氧的消失速率相近。表面氧化物的光谱特征类似于在类似尺寸的Pt纳米颗粒上观察到的氧化物，这为我们提供了一个额外的激励，在高压下使用原位工具重新审视一些单晶模型催化剂表面。
Many interesting structures have been observed for O-2-exposed Pt(110). These structures, along with their stability and reactivity toward CO, provide insights into catalytic processes on open Pt surfaces, which have similarities to Pt nanoparticle catalysts. In this study, we present results from ambient-pressure X-ray photoelectron spectroscopy, high-pressure scanning tunneling microscopy, and density functional theory calculations. At low oxygen pressure, only chemisorbed oxygen is observed on the Pt(110) surface. At higher pressure (0.5 Torr of O-2), nanometer-sized islands of multilayered alpha-PtO2-like surface oxide form along with chemisorbed oxygen. Both chemisorbed oxygen and the surface oxide are removed in the presence of CO, and the rate of disappearance of the surface oxide is dose to that of the chemisorbed oxygen at 270 K. The spectroscopic features of the surface oxide are similar to the oxide observed on Pt nanoparticles of a similar size, which provides us an extra incentive to revisit some single-crystal model catalyst surfaces under elevated pressure using in situ tools.