Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm, Germany.
Phys Chem Chem Phys. 2012 Aug 21;14(31):10919-34. doi: 10.1039/c2cp41434a. Epub 2012 Jul 9.
The adsorption properties of structurally well defined bimetallic Pt/Ru(0001) surfaces, consisting of a Ru(0001) substrate partly or fully covered by monolayer Pt islands or a monolayer Pt film, were studied by temperature programmed desorption (TPD) using CO and deuterium as probe molecules. Additionally, the adsorption of CO was investigated by infrared reflection absorption spectroscopy (IRAS). The presence of the pseudomorphic platinum islands or monolayer film leads to considerable modifications of the adsorption properties for both adsorbates, both on the Pt covered and, to a smaller extent, on the bare Ru part of the surfaces. In addition to distinct weakly bound adspecies, which are adsorbed on the monolayer Pt islands, we find unique contributions from island edge desorption, from spill-over processes during the desorption run, and a general down-shift of the peak related to desorption from Pt-free Ru(0001) areas with increasing Pt coverage. These effects, which we consider as characteristic for adsorption on bimetallic surfaces with large contiguous areas of the respective types, are discussed in detail.
采用程序升温脱附（TPD）技术，利用 CO 和氘作为探针分子，研究了结构明确的双金属 Pt/Ru(0001)表面的吸附特性，该表面由部分或完全被单层 Pt 岛或单层 Pt 膜覆盖的 Ru(0001)衬底组成。此外，还通过红外反射吸收光谱（IRAS）研究了 CO 的吸附。拟形铂岛或单层膜的存在导致两种吸附物的吸附性质发生相当大的变化，不仅在 Pt 覆盖的表面上，而且在较小程度上在裸露的 Ru 部分的表面上也是如此。除了吸附在单层 Pt 岛上的弱结合吸附物种外，我们还发现了来自岛缘脱附、脱附过程中的溢流过程以及与无 Pt 的 Ru(0001)区域相关的脱附峰的普遍下移的独特贡献，随着 Pt 覆盖率的增加，这些贡献来自 Pt 覆盖率的增加。我们认为这些效应是具有大的连续区域的双金属表面吸附的特征，详细讨论了这些效应。
