Synthesis Of Fe-zsm-5 And Application In The Hydroxylation Of Phenol

ZSM-5 zeolite membranes have shown good properties in separation processes and catalytic reactions not only because of their similar pore size to several common material molecules, but also their good stabilities and excellent catalytic performances. By introducing transition metal Fe into the framework of ZSM-5 zeolite membranes, the acidity, pore size and surface structure of the zeolites are all changed. Thus, with their better catalytic performances, Fe-ZSM-5 zeolite membranes show enormous prospect in membrane reactors. The combination of inorganic membrane and reactor is a great breakthrough, therefore, membrane catalysis is known as the most promising direction in catalysis. The integration of reaction and separation in catalytic membrane reactors can reduce energy consumption, and make the reaction free of the limitation of chemical equilibrium. In particular, interphase membrane reactor avoids the use of organic solvents and simplifies the reaction process for immiscible reactants. Compared with reactions catalyzed by zeolite crystal grains, membrane reaction processes can be carried out under continuous and steady-state operation, therefore, the automatic control are easy to realized.Diphenol(including catechol and hydroquinone) are important chemical materials with a wide range of industrial applications. The hydroxylation of phenol with H2O2 is the most promising route for diphenol production because it is one-step process with mild reaction conditions and environmentally benign nature. Currently, the main problem is to find high efficient catalysts for the hydroxylation of phenol. Once the suitable catalysts are found, it will be a major breakthrough in hydroquinone production. According to literature reports, the element of Fe shows good catalytic activities for the hydroxylation of phenol. Using the seeded growth method, the continuous Fe-ZSM-5 membranes with different Al and Fe contents are prepared on theα-Al₂O₃ substrates based on the previous experience. Then we investigate the effect of different metal contents in Fe-ZSM-5 membranes on catalytic activity in phenol hydroxylation. The results indicate that the membranes show good catalytic activity and the different metal content in the membrane influences both the reaction conversion and the distribution of products.