Study On Synthesis And Catalytic Application Of Organized Mesoporous Alumina

Synthesis and catalytic application of organized mesoporous alumina have been studied in detail. Organized mesoporous aluminas with different structure were prepared by different methods in different source of alumina. The structure was characterized by several measuring technology. The influence of reaction conditions on structure of organized mesoporous alumina has been investigated. Nickel was supported on organized mesoporous alumina by different impregnation method. Several techniques were used to detect the structural characterization of catalyst. In order to discuss the influence of mesoporous structure on catalyst, the Ni-containing catalysts were tested activity for the methanation of carbon monoxide and compared withγ-alumina.Organized mesoporous alumina was synthesized by precipitation of inexpensive inorganic aluminium salts. PEG1540 was used as template, monoamoniurn phosphate as assistant solvent. Specific surface area reaches 250-300m~2/g. Total pore volume is 0.3-0.5 cm~3/g, pore diameter up to 4-6nm and narrow pore size distribution less than 4nm. The pore exhibits wormhole channel motifs and uniform in size and shape. The method overcomes the shortcut of expensive template and alumina source in the synthesis of mesoporous alumina for its simple technology and inexpensive cost. PEG1540 can make the direct-piling and support function in the formation of mesopore. Assistant solvent can improve the mesoporous structure. The pH value of reaction terminal of different inorganic aluminium salts affected on mesoporous structure in different extent. The change of aging, cleaning and calcination condition can also produce important influence on mesoporous structure.Nickel supported on two synthesized organized mesoporous alumina has been prepared by the overloading and equivalent-volume impregnation method. The results show that Ni-containing catalysts supported on two organized mesoporous alumina are much more active than theγ- alumina in the methanation of carbon monoxide. The organized mesoporous alumina synthesized from hydrolysis of organic alumina alkoxide is suitable for preparation of high-loading metal catalyst. It can attribute to its high surface area, strong adsorption ability to metal, higher capacity of nickel, strong interaction between metal and carrier. The organized mesoporous alumina synthesized from precipitation inorganic alumina salts may be valuable in shape selective catalysis for its organized stable structure with narrow pore distribution. The different impregnation method has important influence on the structure, interaction between metal and carrier, catalysis of Ni-containing catalyst supported on mesoporous alumina.