Investigation Of Preparation Process Of High Surface Area Alumina

In catalytic reaction, adsorption, functional materials and so on many fields, alumina materials play important roles for the characteristics of thermal and chemical stability, high mechanical strength. At present, hydrothermal method is one of the most common methods for synthesis of alumina. The synthesized crystal are of highly purity, well distribution and easily controllable. Besides, it costs low energy and can be operated simply. As to supported nano-structured gold catalysts, the morphology of nano structure and high specific surface area have a significant influence on catalytic activity. As a consequence, investigation of preparation process of high surface area alumina becomes a challenging topic.In this paper, with aluminum nitrate as precursor and ammonium carbonate as precipitation agent, Alumina nanorods were prepared with the hydrothermal approach with no template.Via controlling time and temperature, the interaction between the growth process of crystal and its morphology was investigated. It is found that the synthesized porous alumina under the hydrothermal condition of 100 ?,24 h and calcined condition of 800 ? has typical nano-structure and high surface area.On this basis, the paper attempts to prepare for small-scale porous alumina material by enlarging the Al3+ concentration 16 times in the same reactor. Via controlling hydrothermal time, the interaction between the growth process of crystal and its morphology was investigated. To get the desired porous Alumina with the same morphology, the hydrothermal reaction time should be increased to 36 h. Although weakened catalytic performance to some extent, but catalyst production increases substantially. There is also a certain economic benefits.With the recipe above, the paper optimized the synthesis of porous alumina and its large-scale preparation. By analyzing the theory and procedure, a suitable large-scale reactor has been designed both in type and size. Ultimately, a vertical stainless steel hydrothermal syhthesis reactor with volume 20 L and volume charge coefficient 0.2?0.6 is selected to be used, of which volume is 110 times as much as that of solvent before.