Preparation and Characterization of Au/Al<sub>2</sub>O<sub>3</sub> and Au-Fe/Al<sub>2</sub>O<sub>3</sub> Materials, Active and Selective Catalysts in Oxidation of Cyclohexene

Abstract

Monometallic gold and bimetallic gold-iron catalysts supported on alumina were prepared in order to check their activity and selectivity in the reaction of cyclohexene oxidation. Au/Al2O3 was prepared by a deposition precipitation with urea (DPU) method, while the bimetallic catalyst Au-Fe/Al2O3 was prepared by under potential deposition (UPD). The characterization by ICP and EDS showed that very small amount of iron are deposited near gold nanoparticles. However, TEM images showed that the deposition method of iron induced gold nanoparticles sintering. All catalysts were tested in the reaction of cyclohexene oxidation in order to check the influence of both the size of gold particles and the presence of iron on the catalytic activity and selectivity. Small gold nanoparticles were shown be efficient in cyclohexene oxidation where the presence of iron influenced widely the selectivity towards the formation of cyclohexene oxide.