Method for preparing aluminum oxide with large specific surface area

Abstract

The invention relates to a method for preparing aluminum oxide. The method is characterized by comprising the following steps of: dissolving aluminum oxide solid in 0.1-0.5mol/L lauroyl sodium glutamate aqueous liquor to obtain 1-5mol/L aluminum chloride liquor; adding ammonia water or mixed liquor of ammonia water and organic amine into the aluminum chloride liquor, and adjusting pH value to 7-8 so as to obtain Al<3+>:OH<-> in the liquid; standing the liquor for 3-5hours at 20-50 DEG C by lauroyl glutamate ions, wherein the molar ratio is 1: (0.05-3): (1.5-7.5); crystallizing the liquor after standing in a reaction kettle at 100-140 DEG C for 24-96hours; and filtering and washing the crystallizing liquid and roasting in a muffle furnace at 500-700 DEG C for 4-6 hours to obtain solid aluminum oxide. The specific surface area of gamma-aluminum oxide can reach 240-400<m2>/g.

Description

technical field [0001] The invention relates to the field of inorganic synthesis and application, in particular, the invention relates to a method for preparing alumina with a high specific surface area. Background technique [0002] Due to its excellent physical and chemical properties, alumina is widely used in various fields such as machinery, metallurgy, petroleum, chemical industry, electronics, optics, and aerospace. In terms of industrial catalysis, alumina is an excellent catalyst carrier, but its catalytic effect as a carrier is severely restricted due to its shortcomings such as small specific surface area, small pore volume, and large average pore diameter. [0003] At present, the preparation methods of alumina mainly include the following: sol-gel method; carbonic acid decomposition method and neutralization method. Patent CN 102515232A discloses a method for preparing alumina, which uses a sol-gel method to prepare aluminum hydroxide ultrafine crystal powder w...

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Problems solved by technology

Patent CN 102515232A discloses a method for preparing alumina, which uses a sol-gel method to prepare aluminum hydroxide ultrafine crystal powder with a large specific surface area, and obtains ultrafine a-alumina spherical powder after calcination, but due to the use of The aluminum source is organic aluminum alcohol such as aluminum ethoxide, which is relatively expensive, so the production cost is relatively high

Patent CN 101774618A discloses another method for preparing alumina, which uses sodium bicarbonate to decompose sodium aluminate solution, and the specific surface area of ​​the prepared alumina is up to 201m 2 / g, the pore volume is 0.32cm 3 / g, the average pore diameter is 3.27nm; this method is simple in process and easy to operate, but the disadvantage is that the specific surface area is relatively small, and the price of raw material sodium metaaluminate is high, and the cost is high

Patent CN 101993102A discloses another method for preparing alumina, which uses the acid-base neutralization method of sodium metaaluminate and aluminum chloride, and the specific surface area of ​​the prepared alumina is up to 315.9m 2 / g, the pore volume is 0.29cm 3 / g, the pore size is 3.95nm, but the disadvantage is that sodium metaaluminate is expensive and the production cost is high