The Preparation Of High Specific Surface MOFS And Their Catalytic Performance

Organic reactions occupy an important position in the industry, and it can compound kinds of intermediates and final products. The Friedel-Crafts acetoxylation, Diels-Alder reaction and O-acetylation are hotspots of academic research. Recently, metal organic frameworks were gradually applied in organic reactions, providing a wider space for the catalyst research. This topic chose MIL-53(Fe) for further research, which is a typical representative of MILs series materials. Their breathing structure unit is able to change pore volume according to the external conditions, such as different solvent and reactant. Therefore, it is of great significance to study its structure and application. At the same time, Cu-BDC has been found for many years, and the structure stability can well meet the requirements of catalytic reaction.In this subject MIL-53(Fe), different levels of MIL-53(Fe)@SiO2-@Fe3O4 materials and Cu-BDC@y-Al2O3 were synthesized by hydrothermal method. With the above three kinds of materials for XRD, FT-IR, TEM and SEM characterization, I can confirm the performance of the materials. Then the experiment investigated the catalytics effect in Friedel-Crafts acylation reaction, Diels-Alder reaction and O-acylation reaction.MIL-53(Fe) was used in the Friedel-Crafts acylation reaction between the benzoyl chloride and paraxylene in solvent-free under the condition of 130?, and the catalyst's quality was 12% of the quality of benzoyl chloride. When the reactants np-xylene:nbenzoyl chloride was 5:1, the conversion rate of benzoyl chloride was 79.25% after 1 h. The catalyst was used repeatedly for five times at the same conditions, and the conversion rate was 65.23%, showing good catalytic performance.MIL-53(Fe)@SiO2@Fe3O4 was used in the Diels-Alder reaction between myrcene and methyl acrylate under solvent-free conditions. The reaction carried in the oil bath at 100?. When the ratio of reactants nmycrene:nmethyl acrylate was 1:1.1 and 0.05g 55.95% MIL-53(Fe)@SiO2@Fe3O4 was used, the conversion rate of myrcene was 72.15% and the selectivity of the para ester was 64.33%.I tried four kinds of solvents on the reaction and found no obvious increase. Therefore, under laboratory conditions to explore the best catalytic reaction conditions, the stability of the pure MIL-53(Fe) after coating on the magnetic core got very big enhancement and the materials with the application of magnetic nuclear magnetic can be conveniently separated from the reaction mixture.Cu-BDC@?-Al2O3 was used for the reaction between benzyl alcohol and acetic anhydride. Under solvent-free conditions, the quality of 31.67% Cu-BDC@y-Al2O3 was 15% of benzyl alcohol, the reaction temperature was 80?, the reaction ratio nacetic anhydride:nbenzyl alcohol was 3:1, and the reaction conversion rate was 80.09% after 3 h. At the same time when the material was repeatedly used for 5 times, it still had good catalytic effect.