Magnetic Fe3O4-Supported Gold Nanoflowers with Lattice-Selected Surfaces: Preparation and Catalytic Performance.

Abstract

Nanoflowers (NFs)—shape-controlled noble metal nanocrystals—have garnered significant attention because of their novel catalytic properties and applicability. In this paper, we report the preparation and catalytic performance of a magnetic Fe3O4-supported AuNF catalyst with a clean surface. The magnetically supported AuNFs were obtained by using magnetic Fe3O4 as the support. However, when nonmagnetic γ-Al2O3 was utilized as the support, the AuNFs did not exhibit a magnetic response. These supported AuNFs were utilized to catalyze the oxidation of 1-phenylethyl alcohol to acetophenone using air (1 atm) as the oxidant. The rate of formation of acetophenone using supported AuNFs was 8-fold higher than that of acetophenone using supported spherical Au nanoparticles of comparable size. In addition, the Fe3O4-supported AuNFs exhibited a higher rate of formation of acetophenone than the Al2O3-supported AuNFs. The Fe3O4-supported AuNFs were recovered using a magnet, and the recovered catalyst was reused under identical catalytic reaction conditions. The rate of formation of acetophenone using recovered Fe3O4-supported AuNFs remained unchanged, demonstrating no loss of catalytic activity.