Highly Efficient Epoxidation of Cyclopentene Catalyzed by Magnetically Recoverable Mg-doped Cobalt Ferrites with Greatly Improved Performances

Abstract

The alkaline earth metal Mg-doped CoFe2O4 composite ferrite samples MgxCo1-xFe2O4 (x=0, 0.1, 0.3, 0.5, 0.7 and 1) were prepared using a sol-gel auto-combustion route. The as-prepared samples were characterized by Raman spectrometry, X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), ICP–atomic emission spectroscopy and N2-physisorption. The catalytic activities of the samples were tested in the cyclopentene oxidation using hydrogen peroxide (30 %) as the oxidant. Compared with the pristine CoFe2O4 and MgFe2O4, the Mg−Co composite ferrites showed much enhanced catalytic performances in the oxidation of cyclopentene with cyclopentene oxide as the main product. In particular, 95.2 % of cyclopentene conversion and 96.3 % of selectivity for cyclopentene oxide were achieved when Mg0.5Co0.5Fe2O4 was used at 60 oC for 8 h in the oxidation reaction. The catalyst can be easily separated by applying magnetic field and exhibits great reusability.