SrFe2O4 complex oxide an effective and environmentally benign catalyst for selective oxidation of styrene

The SrFe2O4 spinel type catalyst is synthesized by citrate gel method. The precursor and oxide are well characterized by various techniques such as TG-DTG, FT-IR, X-ray diffraction, SEM, and X-ray fluorescence. The crystallization temperature of the spinel particle prepared by citrate gel method is 600 degrees C. which is lower than that of ferrite prepared by other methods. SrFe2O4 catalysts prepared by citrate gel method show high activity for styrene oxidation in the presence of H2O2 (30%) as an oxidizing agent and aqueous medium. GCMS analysis revealed that, during the course of reaction, the oxidative cleavage of C=C double bond of styrene takes place selectively to give benzaldehyde selectivity up to 64 mol%, whereas phenyl acetaldehyde selectivity 28 mol% and others' selectivity 8 mol% as minor product. Solvents have marked influence on the product distribution in the selective oxidation of styrene: water seems to be the best solvent. The optimization and effect of various reaction conditions on the conversion of styrene and product distribution were also studied. The highest benzaldehyde yield was obtained at 70 degrees C in water solvent over 0.1 g of catalyst with 18 h of reaction. (C) 2010 Elsevier B.V. All rights reserved.