Interaction of NO with Au nanoparticles supported on (100) terraces and topological defects of MgO

SURFACE SCIENCE

卷:605

Article

Fuente, Silvia A.^1,2  Ferullo, Ricardo M.^1,2  Domancich, Nicolas F.¹  Castellani, Norberto J.¹ 

[1] Univ Nacl Sur, Dept Fis, Grp Mat Sistemas Catalit, RA-8000 Bahia Blanca, Buenos Aires, Argentina

[2] Univ Nacl Sur, Dept Quim, RA-8000 Bahia Blanca, Buenos Aires, Argentina

关键词: Nitric oxide;    Au/MgO;    Model catalysts;    NO adsorption;    DFT;    Cluster model;   

DOI  :  10.1016/j.susc.2010.10.003

来源: Elsevier

【 摘 要 】

The adsorption of nitric oxide (NO) on Au-n (n = 1-3) particles deposited on anionic (O2-) sites of MgO has been studied using the DFT (Density Functional Theory) approach. The regular O2- sites of MgO(100) and the sites in edge and corner topological defects with high symmetry of MgO were considered. The adhesion energy of Au-n to MgO is larger for Au-2 and Au-3 due to higher polarization effects. On the other hand, the interaction strength of NO with supported Au-n particles depends mainly on the electronic configuration (open or closed shell) of the particle; the Au particles with odd number of atoms show larger NO binding energies. A comparison was performed with the reactivity of free Au-n particles. From this, it is possible to conclude that the support enhances the NO-Au-n bonding strength for the monomer, weakens this interaction in the case of the dimer, and does not have an effect in the trimers. Besides, the NO-Au-n bonding is essentially insensitive to the coordination of the anionic site where the Au-n particle is linked. A large red-shift of the N-O stretching frequency was obtained, particularly for the Au particles with odd number of atoms, due to a negative charge transfer from Au to NO. (C) 2010 Elsevier B.V. All rights reserved.

【 授权许可】

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