title: Dumbbell-like Au0.5Cu0.5@Fe3O4Nanocrystals: Synthesis, Characterization, and Catalytic Activity in CO Oxidation.
abstract: We report the colloidal synthesis of dumbbell-like Au0.5Cu0.5@Fe3O4nanocrystals (AuCu@FeOx NCs) and the study of their properties in the CO oxidation reaction. To this aim, the as-prepared NCs were deposited on γ-alumina and pretreated in an oxidizing environment to remove the organic ligands. A comparison of these NCs with bulk Fe3O4-supported AuCu NCs showed that the nanosized support was far more effective in preventing the sintering of the metal domains, leading thus to a superior catalytic activity. Nanosizing of the support could be thus an effective, general strategy to improve the thermal stability of metallic NCs. On the other hand, the support size did not affect the chemical transformations experienced by the AuCu NCs during the activation step. Independently from the support size, we observed indeed the segregation of Cu from the alloy phase under oxidative conditions as well as the possible incorporation of the Cu atoms in the iron oxide domain.
authors.affiliation: Dipartimento di Chimica e Chimica Industriale, Università di Genova , via Dodecaneso 31-I, 16146 Genova, Italy.
authors.forename: Sharif
authors.initials: S
authors.lastname: Najafishirtari
authors.affiliation: Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil.
authors.forename: Tathiana Midori
authors.initials: TM
authors.lastname: Kokumai
authors.forename: Sergio
authors.initials: S
authors.lastname: Marras
authors.affiliation: Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil.
authors.forename: Priscila
authors.initials: P
authors.lastname: Destro
authors.forename: Mirko
authors.initials: M
authors.lastname: Prato
authors.forename: Alice
authors.initials: A
authors.lastname: Scarpellini
authors.forename: Rosaria
authors.initials: R
authors.lastname: Brescia
authors.forename: Aidin
authors.initials: A
authors.lastname: Lak
authors.forename: Teresa
authors.initials: T
authors.lastname: Pellegrino
authors.affiliation: Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil.
authors.forename: Daniela
authors.initials: D
authors.lastname: Zanchet
authors.forename: Liberato
authors.initials: L
authors.lastname: Manna
authors.forename: Massimo
authors.initials: M
authors.lastname: Colombo
keywords: AuCu; CO oxidation; bimetallics; dumbbells; nanocrystals