Promotional effect of short-chain saturated alcohols on Fe3O4-catalyzed decomposition of H2O2 and its application in selective oxidation of benzyl alcohol

BACKGROUNDHydrogen peroxide (H2O2) has been used widely in diverse areas of biotechnology, environmental remediation and organic synthesis wherein its catalytic activation to generate reactive oxygen species (e.g. hydroxyl radicals) is of vital importance. Magnetite (Fe3O4) microspheres are attractive heterogeneous peroxidase-like catalysts due to many technological advantages (e.g. biocompatible, stable and magnetically recoverable). However, its peroxidase-like activity has to be improved for practical applications. RESULTSSmall amounts of short-chain saturated alcohols (e.g. methanol, ethanol, iso-propanol, tert-butanol, mono-ethylene glycol and glycerol) increased collision frequency between H2O2 and Fe3O4 (e.g. by about two orders of magnitude with the addition of 1 mol% glycerol) via facilitating the nucleophilic addition of H2O2 to surface Fe sites and promoted Fe3O4-catalyzed decomposition of H2O2 and selective oxidation of benzyl alcohol with H2O2 in water. In addition, Fe3O4 microspheres were magnetically recoverable and reusable for at least five times without loss of catalytic activity and selectivity. CONCLUSIONSThe Fe3O4/trace alcohol catalytic system decomposed H2O2 effectively. Its potential application was demonstrated by selective oxidation of benzyl alcohol with H2O2 in water in this work. This simple and efficient catalytic system may be applied also to other oxidative transformations in organic syntheses, or to oxidative degradation of organic pollutants in environmental remediation. (c) 2019 Society of Chemical Industry