DFT study on the reaction of NO oxidation on a stepped gold surface

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Jose L C Fajin (Autor) FCUP; Natalia N D S Cordeiro (Autor) FCUP; Jose R B Gomes (Autor) Outra

Revista

Título: Applied Catalysis A: General

Vol. 379 Nº 1-2

Páginas: 111-120

ISSN: 0926-860X

Editora: Elsevier

Indexação

ISI Web of Knowledge - 27 Citações

Scopus - 30 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-003-6PQ

DOI: 10.1016/j.apcata.2010.03.010

Abstract (EN): The NO oxidation either with atomic or molecular oxygen on the stepped Au(3 2 1) surface was studied by means of OFT calculations (GGA/PW91). A periodic supercell approach was used to model the gold stepped surface and the kinetic profiles of the reactions were determined with the dimer approach. It was found that the co-adsorption of NO and O occurs preferentially with these species interacting with top and hollow sites nearby the steps, respectively. In the case of co-adsorbed NO and O(2) species, the most stable configuration on the surface is a ONOO* intermediate. The NO(2) product adsorbs strongly on the Au(3 2 1) surface (E(ads) = -1.10 eV) also nearby the step. The reaction of NO oxidation by atomic oxygen has an energy cost of 0.07 eV, whereas moderate-low energy barriers of 0.21 and 0.25 eV were computed for the reaction with molecular oxygen, via the ONOO* intermediate, following Elay-Rideal (ER) or Langmuir-Hinshelwood (LH) mechanisms, respectively. The reaction route following the ER mechanism is energetically more favorable since it is unnecessary to overcome the very high barriers (similar to 1 eV) needed for NO(2) desorption and for dissociation of molecular oxygen in the cases of NO reaction via LH mechanism and NO oxidation with atomic oxygen, respectively.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10