Supported Gold Nanoparticles as Catalysts in Peroxidative and Aerobic Oxidation of 1-Phenylethanol under Mild Conditions

The efficiency of Au/TiO2 based catalysts in 1-phenylethanol oxidation was investigated. The role of support modifiers (La2O3 or CeO2), influence of gold loading (0.5% or 4%) and redox pretreatment atmosphere, catalyst recyclability, effect of oxidant: tert-butyl hydroperoxide (TBHP) or O2, as well as the optimization of experimental parameters of the reaction conditions in the oxidation of this alcohol were studied and compared with previous studies on 1-octanol oxidation. Samples were characterized by temperature-programmed oxygen desorption (O2-TPD) method. X-ray photoelectron spectroscopy (XPS) measurements were carried out for used catalysts to find out the reason for deactivation in 1-phenylethanol oxidation. The best catalytic characteristics were shown by catalysts modified with La2O3, regardless of the alcohol and the type of oxidant. When O2 was used, the catalysts with 0.5% Au, after oxidative pretreatment, showed the highest activity in both reactions. The most active catalysts in 1-phenylethanol oxidation with TBHP were those with 4% Au and the H2 treatment, while under the same reaction conditions, 0.5% Au and O2 treatment were beneficial in 1-octanol oxidation. Despite the different chemical nature of the substrates, it seems likely that Au+(Auδ+) act as the active sites in both oxidative reactions. Density functional theory (DFT) simulations confirmed that the gold cationic sites play an essential role in 1-phenylethanol adsorption.

Effect of pretreatment atmosphere of WOx/SiO2 catalysts on metathesis of ethylene and 2-butene to propylene

Effect of H2 pretreatment on the non-calcined and air-calcined WO3/SiO2 catalysts.

Biosynthesized Pd/γ-Al2O3 catalysts for low-temperature 1,3-butadiene hydrogenation: the effect of calcination atmosphere

The effect of pretreatment atmosphere on 1,3-butadiene hydrogenation over biosynthesized Pd/γ-Al2O3 catalysts was reported.

Effect of pretreatment atmosphere on the activity and selectivity of Co/mesoHZSM-5 for Fischer–Tropsch synthesis

Co/mesoHZSM-5 pretreatment in different atmospheres changes FT activity and CH4 selectivity by affecting Co dispersion and reducibility.