Formation and characterization of Rh-Mo bimetallic layers on the TiO2(110) surface

SURFACE SCIENCE

卷:603

Article

Kiss, Janos¹ 

[1] Hungarian Acad Sci, Chem Res Ctr, React Kinet Res Lab, Inst Nanochem & Catalysis, H-6701 Szeged, Hungary

关键词: TiO2(110);    Mo;    Rh;    Bimetallic;    Alloying;    Encapsulation;    Thermal activation;    Interfacial reaction;   

DOI  :  10.1016/j.susc.2009.07.045

来源: Elsevier

【 摘 要 】

The investigation of Rh, Mo and Rh-Mo nanosized clusters formed by physical vapor deposition on TiO2(1 1 0) single crystal was performed by X-ray Photoelectron Spectroscopy (XPS), Low Energy Ion Scattering (LEIS) and Auger Electron Spectroscopy (AES). There was no sign for site-exchange between Mo and Rh atoms during deposition of Mo onto Rh particles at 330 K. Mixing between Ti and Mo ions was facilitated at the Mo particle-titania interface due to reaction at 550-700 K. The redox process between titania and Mo deposit was hindered at 330 K by forming predeposited rhodium layer (Theta(Rh) = 2.0 ML), but reached nearly the same extent as without Rh after moderate heating to 600 K. The encapsulation of Rh by titania was complete by about 700 K in the presence of 1.2 ML Mo, in case of Mo-predeposition and Mo-postdeposition as well. Elevating the temperature of TiO2/Rh-Mo layers above 700 K, these metals form alloy at the Mo-Rh interface irrespective of deposition sequences. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

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