Significant improvement of styrene oxidation over zinc phthalocyanine supported on multi-walled carbon nanotubes

•Novel ZnPc–MWCNTs catalyst was prepared by facile ultrasonic impregnation method.•The as-prepared ZnPc–MWCNTs catalyst were firstly used for styrene oxidation.•The ZnPc–MWCNTs exhibited excellent catalytic activity in styrene oxidation.•The MWCNTs prevented the congregation of ZnPc and increased the active sites.•Possible ZnPc–MWCNTs catalytic mechanism for styrene oxidation was discussed.

A novel hybrid catalyst (ZnPc–MWCNTs) was facilely prepared by a ultrasonic impregnation method. The as-prepared hybrid materials were characterized by FT-IR spectra, X-ray diffraction (XRD), diffuse reflectance spectra (DRS), scanning electron microscope (SEM), Raman spectroscopy and transmission electron microscopy (TEM). This hybrid material was employed as catalyst for styrene oxidation in presence of hydrogen peroxide as oxidant. The results showed that styrene was oxidized efficiently in the ZnPc–MWCNTs/H2O2 system. The enhancement of the catalytic activity of ZnPc–MWCNTs hybrid materials was investigated in terms of different oxidation conditions. It was found that the optimum oxidation condition was 40 mg catalyst, 8 h reaction time and reaction temperature of 60 °C. Under this condition, the conversion and the selectivity of styrene oxide was up to 94% and 90.6%, respectively. Moreover, the catalytic mechanism of styrene oxidation to benzaldehyde by the ZnPc–MWCNTs hybrid was also discussed.

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