The Preparation Of High Surface Area Pseudoboehmite And The Catalytic Properties Of Metal Organic Frameworks

Pseudoboehmite is the fold flaky crystal with incomplete crystallization,having high surface area and large pore volume.It is widely used in catalyst preparation,coating additives,high-grade ceramic preparation,cosmetic fillers etc.Among them,pseudoboehmite is mainly used for the catalyst preparation.In order to increase the catalytic efficiency of the catalyst,preparation of large pore volume and high surface area become more and more important.In this paper,the pseudoboehmite was prepared by precipitation method in different 1234 solution(21,31,32,41,42,43,44),using aluminum nitrate with nine water as aluminum source and ammonia as the precipitating agent.The products was characterized by X-ray powder diffraction(XRD),infrared spectroscopy(IR),transmission electron microscopy(TEM),scanning electron microscopy(SEM),N2 adsorption-desorptionn measurements(BET),respectively.The polymorphs,morphology and pore properties of products and corresponding calcined products were studied.The results show that only when the volume of the 00 content exceeds 60%,the surface area and pore volume of products can be effectively improved and high surface area(475m2/g)and large pore volume(1.91cm3/g)could be realized.After calcinations,the products still have high surface area and large pore volume.In addition,expoxidation of styrene were catalyzed using various CuO-γ-Al2O3,prepared in different 1234 solution.Compared with the aqueous product,the catalytic properties were greatly improved.In addition,the metal organic framework Cu(BDC)was synthesized by solvothermal method,using copper nitrate and terephthalic acid as raw material and dimethyl formamide(DMF)as solvent.The product was characterizated using X-ray diffraction(XRD),infrared spectroscropy(IR),scanning electron microscopy(SEM),respectively.After studying the catalytic properties of Cu(BDC)for epoxidation of styrene and screening the oxidizing agent,reaction temperature,reaction time,sovent influence on styrene conversion and styrene oxide selectivity,the suitable condition was obtained.Under certain conditions,the conversion of styrene(97%)and the selectivity of ethylene oxide(43%)could be reached.