Thermal Evolution and Instability of CO-Induced Platinum Clusters on the Pt(557) Surface at Ambient Pressure

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• 作者：Jeongjin Kim ; Myung Cheol Noh ; Won Hui Doh ; Jeong Young Park
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：February 3, 2016
• 年：2016
• 卷：138
• 期：4
• 页码：1110-1113
• 全文大小：371K
• ISSN：1520-5126

文摘

Carbon monoxide (CO) is one of the most-studied molecules among the many modern industrial chemical reactions available. Following the Langmuir–Hinshelwood mechanism, CO conversion starts with adsorption on a catalyst surface, which is a crucially important stage in the kinetics of the catalytic reaction. Stepped surfaces show enhanced catalytic activity because they, by nature, have dense active sites. Recently, it was found that surface-sensitive adsorption of CO is strongly related to surface restructuring via roughening of a stepped surface. In this scanning tunneling microscopy study, we observed the thermal evolution of surface restructuring on a representative stepped platinum catalyst, Pt(557). CO adsorption at 1.4 mbar CO causes the formation of a broken-step morphology, as well as CO-induced triangular Pt clusters that exhibit a reversible disordered–ordered transition. Thermal instability of the CO-induced platinum clusters on the stepped surface was observed, which is associated with the reorganization of the repulsive CO–CO interactions at elevated temperature.