Highly selective oxidation of benzyl alcohol to benzaldehyde with hydrogen peroxide by cobalt aluminate catalysis: A comparison of conventional and microwave methods

A comparative study of the structural, optical and catalytic properties of CoAl2O4 nanoparticles is reported. Cobalt aluminate (CoAl2O4) nano and microstructures were synthesized by both conventional and microwave methods using Sesame (Sesamum indicum, L.,) as a plant extract. The use of Sesame extract provides an alternative method for a simple and economical synthesis of cobalt aluminate. Synthesized cobalt aluminate powder were characterized by X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption isotherms, diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) studies. CoAl2O4 prepared by the microwave method was found to possess a higher surface area, and lower crystallite size than the one prepared by the conventional method, which in turn leads to the improved performance towards the selective oxidation of benzyl alcohol to benzaldehyde.