Copper, copper oxide nanoparticles and copper complexes supported on mesoporous SBA-15 as catalysts in the selective oxidation of benzyl alcohol in aqueous phase

Copper(II) complexes, copper and copper oxide nanoparticles supported on SBA-15 have been prepared and their catalytic performance in benzyl alcohol oxidation in aqueous phase studied. Hybrid mesoporous SBA-15 functionalized with imidazole ionic liquid and functionalized with an amino alcohol chelate ligand have been used as solid supports in order to tether copper(II) complexes. From these materials, copper nanoparticles and copper oxide nanoparticles supported on SBA-15 have also been synthesized. Copper based materials have been characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), N-2 adsorption-desorption, transmission electron microscopy (TEM) with microanalysis by energy-dispersive X-ray (EDX), solid-state nuclear magnetic resonance spectroscopy (CP-MAS-NMR), Fourier-transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (DRUV-vis), thermogravimetric analysis (TG-DTG) and electrochemical techniques. The catalyst synthesized by immobilization of ionic liquid containing copper and followed by chemical reduction method showed the highest activity in the oxidation of benzyl alcohol with a 73% conversion and 54% selectivity of benzaldehyde (30 min reaction time). The stability of the catalysts has been also examined by voltammetry measurements. (C) 2015 Elsevier Inc. All rights reserved.