Efficient catalytic wet peroxide oxidation of phenol over Fe-ZSM-5 catalyst in a fixed bed reactor

Abstract

Fe-ZSM-5 catalyst was prepared for catalytic wet peroxide oxidation (CWPO) of phenol in a fixed bed reactor. The catalyst was prepared by incipient wetness impregnation and characterized by using N2 adsorption–desorption and X-ray diffraction (XRD). The optimum operation conditions for catalytic wet peroxide oxidation of phenol over Fe-ZSM-5 catalyst were determined by investigating the effects of feed flow rate and catalyst bed height on the conversion of phenol, H2O2 and total organic carbon (TOC). In addition, stability and reusability of the Fe-ZSM-5 catalyst was studied by measuring the iron concentration leached out from the catalyst. Finally, the probable reaction mechanism of phenol oxidation over Fe-ZSM-5 catalyst in the fixed bed reactor was considered by analyzing the HPLC patterns. The experimental results showed that the Fe-ZSM-5 catalyst achieved the highest activity (99.2% phenol conversion and 77.7% TOC conversion, respectively) with remarkable low iron leaching concentration closed to zero at the temperature of 80°C, feed flow rate of 2mL/min and catalyst bed height of 3.8cm. The Fe-ZSM-5 catalyst showed a perfect stability with low iron leaching concentration (about 1.0mg/L) and high phenol conversion (above 95.0%) after three successive runs. Meanwhile, few intermediate products with low concentration were observed by the analysis of HPLC patterns for the CWPO of phenol in the fixed bed reactor.