title: Sonochemical oxidation of vanillyl alcohol to vanillin in the presence of a cobalt oxide catalyst under mild conditions.
abstract: The heterogeneous oxidation of vanillyl alcohol to vanillin was investigated on new grounds under eco-friendly conditions in the presence of hydrogen peroxide as an oxidant and water as solvent, coupled with low frequency ultrasonic irradiation. The sono-Fenton-like-assisted vanillyl alcohol oxidation was performed with a high-surface area nanostructured spinel cobalt oxide catalyst exhibiting small crystallites size. The catalytic reaction was also carried out under conventional heating conditions for comparison purposes. The influence of the reaction parameters, namely catalyst loading and hydrogen peroxide concentration was studied with the aim of determining the optimum yield and selectivity to the desired vanillin product. The chemical effects of ultrasound (ability to generate hydroxyl radicals) along with increased mass transfer appeared to be key prerequisites for enhancing the efficiency of the process, while decreasing the overall energy consumption.
authors.affiliation: Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, CNRS, ENSIP, B1, 1 rue Marcel Doré, F-86073 Poitiers Cedex 9, France.
authors.forename: Ronan
authors.initials: R
authors.lastname: Behling
authors.affiliation: Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, CNRS, ENSIP, B1, 1 rue Marcel Doré, F-86073 Poitiers Cedex 9, France; Present address: Laboratoire de Chimie Moléculaire et Environnement (LCME), Université Savoie Mont Blanc, 73376 Le Bourget du Lac Cedex, France. Electronic address: gregory.chatel@univ-smb.fr.
authors.forename: Gregory
authors.initials: G
authors.lastname: Chatel
authors.affiliation: Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, CNRS, ENSIP, B1, 1 rue Marcel Doré, F-86073 Poitiers Cedex 9, France. Electronic address: sabine.valange@univ-poitiers.fr.
authors.forename: Sabine
authors.initials: S
authors.lastname: Valange
mesh_terms: D001547:Benzaldehydes / Q000737:chemistry*; D001592:Benzyl Alcohols / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D000069453:Ultrasonic Waves
chemical_list: D001547:Benzaldehydes; D001592:Benzyl Alcohols; D010087:Oxides; D017665:Hydroxyl Radical; D003035:Cobalt; C100058:vanillin; C060728:cobalt oxide; C024078:vanillyl alcohol
keywords: Cobalt oxide catalyst; Hydrogen peroxide; Selective oxidation; Sonochemistry; Ultrasound