Heather Abbott-Lyon - CO adsorption on monometallic and bimetallic Au-Pd nanoparticles supported on oxide thin films

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      Publication Details (including relevant citation   information):

      H.L. Abbott, A. Aumer, Y. Lei, S. Asocan, R.J.   Meyer, M. Sterrer, S. Shaikhutdinov, and H.-J. Freund,   Journal of Physical Chemistry C accepted (2010).

      Abstract:

      Supported Au-Pd catalysts have been shown to exhibit superior   catalytic performances when compared to their monometallic   counterparts in a variety of reactions. In addition, the nature   of the support often plays a critical role in reactivity. To gain   a deeper understanding of the structure-reactivity relationship   of the Au-Pd catalysts, here we have employed model systems where   monometallic and bimetallic Au-Pd nanoparticles are deposited on   well-ordered thin films of reducible and irreducible oxides   (i.e., Fe3O4(111), MgO(100), and CeO2(111)). Surface structures   of the model systems were characterized by temperature-programmed   desorption, sum frequency generation, and infrared reflection   absorption spectroscopy of CO as a probe molecule. In agreement   with previous studies, the results show segregation of gold to   the surface. Density functional theory calculations confirm that   Au prefers to be at the edges of AuPd alloy particles under   vacuum conditions. Strong similarities between the spectral   features observed for metal particles on these oxide substrates   suggest that the reducibility of the support does not affect the   surface structure.

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