Formation of nitric oxide dimers on MgO-supported gold particles

SURFACE SCIENCE

卷:606

Article

Fuente, Silvia A.²  Fortunato, Leandro F.¹  Domancich, Nicolas²  Castellani, Norberto J.²  Ferullo, Ricardo M.¹ 

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

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

关键词: Au/MgO;    Gold clusters;    N2O2;    Nitric oxide;    DFT;    Cluster model;   

DOI  :  10.1016/j.susc.2012.08.003

来源: Elsevier

【 摘 要 】

We present density functional theory (DFT) calculations on the formation of nitric oxide dimers (N2O2) on Au atoms, dimers and trimers adsorbed on regular O2- sites and neutral oxygen vacancies (F-s sites) of the MgO(100) surface. The study of the N2O2 species is of great interest since it has been detected in the NO reduction reaction as an intermediate towards the formation of N2O. We found that the coupling of a NO molecule with a previously adsorbed one on Au/MgO is energetically favorable on Au-1 and Au-3, but unfavorable on Au-2. The stability of N2O2 is in direct relation with the amount of charge taken from the support. Furthermore, one of the N-O bonds can be activated as a result of the attraction between the negatively charged NO dimer and the ionic oxide surface. In fact, for Au-1 anchored on the F-s site a barrierless reaction occurs between N2O2 and a third NO molecule, forming adsorbed N2O and NO2. (c) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

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