Selective liquid Phase oxidation of cyclohexene catalyzed by NiO nanoparticles supported on mesoporous MCM-41

Abstract

The nanoparticles of NiO supported on mesoporous MCM-41 were synthesized and were well characterized with X-ray diffraction (XRD) and transmission electron microscopy (TEM). In this research catalytic activities of the supported NiO nanoparticles for cyclohexene oxidation to 2-cyclohexene-1-ol, cyclohexenone and cyclohexene oxide with tert-butylhydroperoxide (TBHP) and hydrogen peroxide (H2O2) as the oxidant, in the presence of solvent were studied. For the n%NiO/MCM-41 nanocomposites (n = 5, 10 and 15% NiO), a dimethylformamide:dichloromethane (3:7) solvent mixture was applied. To achieve higher conversion of cyclohexene and better selectivity toward main products, factors such as oxidant type, solvent and the loading amount of nickel oxide were studied, and optimized conditions were investigated. tert-Butylhydroperoxide was specified to be better oxidant than hydrogen peroxide as higher activity of catalyst were observed when TBHP was used. Among used nanocomposites, 10%NiO/MCM-41 exhibit the highest activity in this oxidation reaction. With mesoporous MCM-41 supported 10% NiO and under these reaction conditions, the conversion percent of cyclohexene is 82.9% with 67.5% selectivity of cyclohexenone.

Keywords

• oxidation
• nickel oxide
• support
• cyclohexene
• nanocomposites