Preparations Of Solid Acid Catalysts And Their Catalytic Synthesis Of 1-phenyl-1-xylyl Ethane

Diphenylethane (PXE) is a colorless synthetic liquid with many excellent properties, such as high-boiling point, small viscosity, low-pour point, strong color ability and high voltage-resistance,which are suitable for various industrial applications, e.g., a solvent for pressure-sensitive record materials, electric-insulating oil etc. At present, The PXE products depend mainly on abroad. So it is significant to study new catalytic synthesis methods of PXE both theoretically and industrially.The effects of preparation conditions such as the templates, Si-Al ratio on the synthesis of molecular sieve A1-MCM-41 were discussed. The results showed that the optimal conditions were: Na2SiO3 as silica source, Al2(SO4)3 as aluminum source, and cetyltrimethylammonium bromide (CTAB) as template agent under hydrothermal condition. The composition and configuration of A1-MCM-41 molecular sieve are determined by characterization of X-ray diffraction (XRD), thermogravimetry differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and infrared spectroscopy (IR).The proper conditions of preparating supported catalyst PW/HM have been obtained: it was prepared by ultrasonic treatment during the impregnation step, with HM zeolite as a carrier. Structural and physical properties of the catalysts were characterized by XRD,IR,SEM and TEM.Two kinds of catalysts Al-MCM-41 mesoporous sieves catalysts and H3PW12O40 supported mordenite(HM)catalysts have been prepared in this thesis. The synthesis of diphenylethane with these catalysts and their catalytic performance were investigated. The optimal conditions were: the mass percent of catalyst was 1 % of feed stock; the weight ratio of xylene to styrene was 7.5: 1; the reaction temperature was 140°C and the time was 3 h. The yield of diphenylethane under such conditions was about 87.1 %, which was 17 % higher than that catalyzed by sulfuric acid. The results showed that Al-MCM-41 and PW-HM might be promising solid acid catalysts instead of liquid acid for synthesis of diphenylethylane. The solid acid can be used to eliminate the corrosion of equipment, and avoid discharge of waste acid and waste water. This work provides a theoretical basis on systhesizing PXE with solid acid as catalyst.