Preparation of ZSM-5 containing vanadium and Brønsted acid sites with high promoting of styrene oxidation using 30% H₂O₂

Design and synthesis of low cost and efficacious industrial catalyst for the oxidation of styrene has been an important research project. Herein, ZSM-5 zeolite containing tetrahedral vanadium (V) and Brønsted acid sites (V-H-ZSM-5) was prepared, and identified by characterizations such as XRD, SEM, UV–vis, NH₃-TPD, H₂-TPR N₂-adsorption/desorption and FTIR. V-H-ZSM-5 performed extremely enhanced catalytic activity for the oxidation of styrene with 30% H₂O₂ at 40 °C. Moreover, in-situ FTIR spectrum was used to investigate the catalytic mechanism. The results demonstrate that Brønsted acid site could not only increase the adsorption concentration of styrene in the micropores of V-H-ZSM-5 via the π complex interaction between double bond of styrene and Brønsted acid sites, but also increase the oxidation potential of H₂O₂. The synergetic action of tetrahedral vanadium (V) and Brønsted acid enhanced the catalytic activity for the oxidation of styrene with 30% H₂O₂. Impressively, V-H-ZSM-5 performed high reusability within five runs at a low reaction temperature (40 °C) for the first time.