双金属片
原位
金属
过渡金属
铂金
低能离子散射
分析化学(期刊)
作者
Juan Pablo Simonovis,Adrian Hunt,Robert M. Palomino,Sanjaya D. Senanayake,Iradwikanari Waluyo
标识
DOI:10.1021/acs.jpcc.8b00078
摘要
The interaction between a catalyst and reactants often induces changes in the surface structure and composition of the catalyst, which, in turn, affect its reactivity. Therefore, it is important to study such changes using in situ techniques under well-controlled conditions. We have used ambient pressure X-ray photoelectron spectroscopy to study the surface stability of a Pt/Cu(111) single-atom alloy in an ambient pressure of CO. By directly probing the Pt atoms, we found that CO causes a slight surface segregation of Pt atoms at room temperature. In addition, while the Pt/Cu(111) surface demonstrates poor thermal stability in ultrahigh vacuum conditions, where surface Pt starts to diffuse to the subsurface layer above 400 K, the presence of adsorbed CO enhances the thermal stability of surface Pt atoms. However, we also found that temperatures above 450 K cause restructuring of the subsurface layer, which consequently strengthens the CO binding to the surface Pt sites, likely because of the presence of n...
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