Preparation of novel Fe-ZSM-5 zeolite membrane catalysts for catalytic wet peroxide oxidation of phenol in a membrane reactor

摘要

Novel Fe-ZSM-5 zeolite membrane catalysts were prepared for catalytic wet peroxide oxidation (CWPO) of phenol in a membrane reactor. Firstly, the ZSM-5 zeolite membrane with a Si/Al ratio of 80 was fabricated by using secondary growth process on the surfaces of paper-like sintered stainless steel fibers (PSSFs) which was prepared by wet lay-up papermaking process and sintering process. Then, Fe-ZSM-5 zeolite membrane catalysts with Fe loading of 15%, 25% and 35% were prepared and systematically characterized by using X-ray diffraction (XRD), N2 adsorption-desorption, field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), H2-temperature programmed reduction (H2-TPR) and X-ray photoelectron spectra (XPS), respectively. Finally, catalytic activity of Fe-ZSM-5 zeolite membrane catalysts was evaluated by investigating the conversion of phenol, H2O2 and TOC as well as the Fe leaching concentration in the treated effluent based on the CWPO processes in a membrane reactor. The characterization results showed that ZSM-5 zeolite membrane with a thickness of 6 urn was fabricated on the surface of PSSFs and Fe element with a form of Fe2O3 was uniformly dispersed on the surface of ZSM-5 zeolite membrane support. The results of CWPO of phenol showed that the catalyst with Fe loading around 25% achieved the highest activity (phenol conversion about 95% and TOC conversion about 45%, respectively) after continuously ran for 7 h. Meanwhile, low loss of Fe species was observed on all of the catalysts (Fe leaching concentration lower than 7 mg/L).