Dumbbell-like Au 0.5 Cu 0.5 @Fe 3 O 4 Nanocrystals: Synthesis, Characterization, and Catalytic Activity in CO Oxidation

• Published in: ACS applied materials & interfaces 2016-10, Vol.8 (42), p.28624-28632
• Main Authors: Najafishirtari, Sharif, Kokumai, Tathiana Midori, Marras, Sergio, Destro, Priscila, Prato, Mirko, Scarpellini, Alice, Brescia, Rosaria, Lak, Aidin, Pellegrino, Teresa, Zanchet, Daniela, Manna, Liberato, Colombo, Massimo
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.6b09813

We report the colloidal synthesis of dumbbell-like Au Cu @Fe O nanocrystals (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 Fe O -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.