Selective solvent-free oxidation of toluene to benzaldehyde over zeolite supported iron

Iron-modified HZSM-5 materials were prepared by the impregnation techniques at ambient temperature and characterized by X-ray powder diffraction (XRD) and ICP-MS to determine the phase structure and loadings of iron dioxide. This material was tested for solvent-free catalytic oxidation of toluene under mild conditions. The result shows that Fe2O3/HZSM-5 is an effective catalyst, exhibiting 17.3% conversion of toluene, 51.4% selectivity to benzaldehyde at 90 °C. Furthermore, the catalyst can be easily recovered and reused for three times without a significant loss in its activity and selectivity.