Method for preparing porous flaky nano aluminum oxide

Abstract

The invention discloses a method for preparing porous flaky nano aluminum oxide. The method is characterized by comprising the following steps: (1) dissolving soluble salt and an expanding agent into deionized water, and stirring till the soluble salt and the expanding agent are completely dissolved; (2) adding an aluminum precursor into the solution obtained in the step (1), and stirring till the aluminum precursor is completely dissolved; (3) performing hydrothermal crystallization on the solution obtained in the step (2) under a dynamic condition; (4) after hydrothermal treatment, cooling the solution to the room temperature, filtering, washing, drying, and roasting, thereby obtaining the porous flaky nano aluminum oxide. The porous flaky nano aluminum oxide prepared by using the method has the advantages of being large in specific surface area, adjustable in pore, controllable in thickness, good in dispersity, high in thermal stability, rich in pentacoordinate aluminum, and the like.

Description

technical field [0001] The invention belongs to the technical field of preparation of inorganic nanometer materials with controllable morphology, and in particular relates to a method for preparing porous sheet-like nano-alumina which can be used for catalyst carrier or coating. Background technique [0002] Alumina is a basic inorganic material widely used in catalysis, ceramics, coatings, pigments and other fields. It has 9 different crystal forms, and the most widely used ones are activated alumina (γ and η alumina) and α-type alumina. Due to the advantages of large specific surface area, rich pore structure, adjustable pore size distribution, and high surface activity, activated alumina can be used as an adsorbent, catalyst, catalyst carrier / coating, etc. important application. The properties and applications of alumina depend to a large extent on its morphology and structure. Therefore, the synthesis of alumina nanomaterials with special microstructure and controllabl...

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Problems solved by technology

Although the literature on the preparation of flake nano-alumina (Al 2 o 3 Nanosheets Rich in Pentacoordinate Al 3+ Ions Stabilize Pt-Sn Clusters for Propane Dehydrogenation, Angew.Chem.Int.Ed.2015,54,13994-13998.; Synthesis ofγ-Al 2 o 3 Hexagonal Nanoplatelet by Combining Sol–Gel and Hydrothermal Process, Mater.Manuf.Process, 25(2010) 919-922.; Hexagonγ-alumina nanosheets produced with the assistance of supercritical ethanol drying, J.Supercrit.Fluid., 45(2008) 112- 120. Hierarchical Al 2 o 3 Nanobelts and Nanowires:Morphology Controland Growth Mechanism,Cryst.Growth Des.,9(2009)4230-4234.等)和专利(CN200880104559.1,CN201310094967.6,CN201310287413.8,CN201010 296297.2,CN201410142128.1,CN201510128001.9 , CN200710179638.6, etc.) reported more, but the flake alumina prepared by the method reported in the literature still has many shortcomings, such as the difficult control of the alumina crystal structure by the mechanical method, the high energy consumption of the molten salt method, the long reaction cycle, and the Complicated, difficult to control the uniformity, difficult to control the particle size and thickness of alumina by traditional hydrothermal method, easy to agglomerate, poor dispersion, etc.

In addition, due to the small specific surface area of ​​the prepared flaky alumina, difficulty in controlling the crystal phase, excessive thickness of the flake, surface properties, especially the aluminum coordination environment and the lack of surface hydroxyl groups, most of them are only suitable for ceramic powder materials, pigments, Coatings and other fields, while the application in the field of catalyst or carrier (such as solid acid catalyst, noble metal catalyst carrier, automobile exhaust or industrial exhaust gas catalytic combustion monolithic catalyst coating) is limited

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