Oxidation of Styrene to Benzaldehyde by Anhydrous Hydrogen Peroxide on γ‐Alumina‐Supported V₂O₅ Nanoparticle Catalysts: Optimization Studies Using Response Surface Methodology

Abstract

Particles of γ‐alumina‐supported V2O5 with an average particle size of 5‐10 nm and a surface area of 174.8 m2/g were prepared through a wet impregnation method. These materials were found to be effective in the selective oxidation of styrene to benzaldehyde using anhydrous H2O2. Response surface methodology was used to investigate the effect of the oxidant (H2O2) concentration (from 20 to 60 mmol), temperature (from 45 to 75°C), time (from 2.5 to 6 h) and catalyst concentration (from 0.014 to 0.036 g/L) on the styrene conversion and the selectivity of benzaldehyde and styrene oxide. Based on the response surface methodology analysis, the optimal oxidation conditions occur with a reaction temperature of 62.7°C, a reaction time of 5.15 h, a molar ratio of H2O2/styrene of 2.7:1 and a catalyst concentration of 0.024 g/L. These conditions result in maximal styrene conversion (68.23%) and benzaldehyde selectivity (57.32%).

The effects of metals and ligands on the oxidation of n-octane using iridium and rhodium “PNP” aminodiphosphine complexes

“…Similar studies carried out in alkene oxidation showed better conversion in chlorinated solvents. 75,76 It has been shown that some catalytic reactions proceed more efficiently in a mixture of solvents; 77 however, when a 1:1 ratio of DCE/MeCN was used, the reactions with and without the catalyst were comparable.…”

Process Development and DFT‐Assisted Mechanism of the Vapour Phase Ammoxidation of 2,6‐Dichlorotoluene to 2,6‐Dichlorobenzonitrile over the V2O5/γ‐Al2O3 Catalyst

“…The X‐ray diffraction patterns of V 2 O 5 /γ‐Al 2 O 3 catalysts having different V 2 O 5 loadings are shown in Figure . Alumina‐supported vanadium oxide catalysts possess dispersed surface vanadium oxide species up to 15 wt% loading of vanadia, which corresponds to monolayer surface vanadia coverage on the alumina support . As the surface vanadia concentration increases the surface vanadia species begin to polymerize to polycrystalline V 2 O 5 .…”

Heterogeneous Oxidation of Alkenes: The Role of Silica-supported Bimetallic and Trimetallic Catalysts

“…9,16,20 Both TBHP and H 2 O 2 were studied for the styrene oxidation in this work, but THBP was found to be the best source of oxygen. Styrene was chosen as substrate model for the optimization of the catalysis reaction conditions using TBHP as the oxidant in the presence of catalytic amounts of the 10CuNiCoSiO catalyst.…”

“…12,13 For the heterogeneous oxidation of alkenes, there are a number of reports involving the use of mono and bimetallic-supported metal oxides. [14][15][16][17] In addition to that, oxidation of cyclohexene by TBHP catalyzed by a series of titania-silica (TiO 2 -SiO 2 ) mixed oxides prepared by a sol-gel procedure was studied and the effect of water in the reaction medium has also been investigated by Figueras and Kochkar. 18 Titanium oxide-supported zeolite particles have been used as a heterogeneous catalytic system for the oxidation of alkenes with H 2 O 2 as reported by Nur et al 19 , while Nieet et al studied the use of TiO 2 and TiO 2 /SiO 2 as catalysts for the oxidative conversion of styrene to benzaldehyde using O 2 as oxidant.…”