Chitosan modified with cobalt(II) as a green catalyst for the oxidation of styrene to styrene oxide

Chitosan was used as a green support for cobalt(II). Chitosan-cobalt(II) after characterization with common methods including FT-IR, flame atomic absorption spectroscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and thermal gravimetric analysis as a biocompatible heterogeneous catalyst was used in the oxidation reaction of styrene to styrene oxide. The reaction led to the formation of styrene oxide in the presence of the prepared catalyst and excess amounts of hydrogen peroxide as a green oxidant in H2O as the solvent at room temperature during 6 h with 96% yield and high selectivity. Also, the reaction gave high yield in the solvent free conditions. The catalyst is recyclable for six times without any significant decreases in the activity.