Selective oxidation of styrene catalyzed by cerium-doped cobalt ferrite nanocrystals with greatly enhanced catalytic performance

- Ce-doped cobalt ferrites were prepared by a facile, mild, and green route.
- The samples show high activity in styrene oxidation using H2O2 as a green oxidant.
- The Ce-doped samples show greatly enhanced performance over the pristine CoFe2O4.
- The catalysts can be magnetically separated easily and have prominent recyclability.

The rare earth metal Ce-doped cobalt ferrite samples CexCo1−xFe2O4 (x = 0.1, 0.3, 0.5) were prepared by the sol-gel autocombustion route. The as-prepared samples were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, ICP-atomic emission spectroscopy, and N2 physisorption. Their catalytic performance was evaluated in oxidation of styrene using hydrogen peroxide (30%) as oxidant. Compared with pristine CoFe2O4, the Ce-doped samples were found to be more efficient catalysts for the oxidation of styrene to benzaldehyde, with greatly enhanced catalytic performance. Especially, when Ce0.3Co0.7Fe2O4 was used as catalyst, 90.3% styrene conversion and 91.5% selectivity for benzaldehyde were obtained at 90 °C for 9 h reaction. The catalyst can be magnetically separated easily for reuse, and no obvious loss of activity was observed when it was reused in five consecutive runs.

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