Preparation Of Macroporous Pseudo Boehmite Nano Materials

With the rapid development of chemical industry, alumina, especially mesoporous - Alumina is widely used in many chemical reactions because of its large specific surface area, unique surface properties and structural stability. In order to effectively improve the catalytic efficiency, large pore volume and high specific surface area - The preparation of alumina is becoming more and more important. - Alumina is generally prepared by dehydration of pseudo boehmite at high temperature. Therefore, it can be said that the property of precursor pseudo boehmite determines the product - Properties of alumina. In this paper, mesoporous pseudo boehmite was synthesized in micelles of different surfactants, sodium bis (2-ethylhexyl) succinate sulfonate (AOT), cetyltrimethylammonium bromide (CTAB) and polyethylene glycol octyl phenyl ether (Triton X-100) by direct precipitation method, using aluminum nitrate hexahydrate as inorganic aluminum source and ammonia as precipitant. The composition of the product was analyzed by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) and N2 adsorption desorption The results showed that fibrous pseudo boehmite with a diameter of 2-5nm was prepared in AOT system, and agglomerated granular products were obtained in Triton X-100 and CTAB system. In AOT micelle system, pure pseudo boehmite can be prepared when the terminal pH is 8 10.5. In addition, the effects of metal ions on the pore properties of products were studied. It was found that the introduction of different metal ions greatly improved the specific surface area, pore volume and pore diameter of pseudo boehmite. In addition, in the triblock polymer polyoxyethylene polyoxypropylene polyoxyethylene (PEO (20) PPO (70) peo (20), P123) and anionic surfactant 2 Nano metal oxide catalyst CuO was synthesized in the mixed system of sodium ethylhexyl succinate sulfonate (AOT)- - Al2O3, its catalytic performance for epoxidation of styrene was studied. It was found that the main products of the catalytic reaction were benzaldehyde and phenylethylene oxide. The effects of reaction temperature, solvent, molar ratio of oxidant to substrate styrene on the conversion and selectivity of styrene epoxidation were investigated. It was found that CuO- - Al2O3 catalyst has very high conversion (97.43 percent ) for styrene epoxidation, and the selectivity of epoxidation products is also high (85.15 percent ).