QD201 : Preparation and Characterization of Fe3O4 magnetic Nano-particles@Boehmite Functionalized with Molybdenum complex and Investigation of their Catalytic Application
Thesis > Central Library of Shahrood University > Chemistry > MSc > 2013
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Abstarct: In this research at the first step, nano Fe3O4@Boehmite, core-shell Fe@B and Fe@B*was prepared via hydrothermal process for use as catalytic bed. Fe3O4 nano-particles have been prepared by solvothermal method. Then it was grafted by aluminum 2-propoxide to form boehmite shell via hydrothermal assisted sol-gel processing and then characterized by TEM. The advantages of Fe3O4 as catalytic bed in comparison with conventional heterogeneous catalytic beds, is the magnetic properties that cause the easy separation from the reaction mixture. Boehmite with high degree of surface hydroxyl groups have been coated on the surface of Fe3O4 and the stability of the catalytic bed was increased by decreasing the agglomeration of the magnetic Fe3O4 nano-particles. Fe@B* has high surface area and can be easy functionalized by different lixnkers and mextal complexes. In the second step, nano-Fe@B and nano-Fe@B* was covalently functionalized with 3-(tri-methoxy silyl) propyl amine by refluxing in dry toluene. CHN analysis showed that the amount of pending amine group supported on Fe@B-A and Fe@B*-A was 0.19 and 0.26 mmol/g, respectively. Molybdenum hexa-carbonyl then supported on Fe@B-A and Fe@B*-A by refluxing in THF. ICP analysis showed that mextal loadings on Fe@B-A and Fe@B*-A were 0.033 and 0.065mmol/g. Then Fe@B-A-Mo was used in epoxidation of cis-cyclooctene and the yields of reactions were investigated by GC. The catalytic procedure was optimized for different parameters such as amount of catalyst, type and amount of solvent, type and amount of oxidant, temperature and time. It was found that the optimized condition, with over 90% yield, for epoxidation of 0.5 mmol cis-cyclooctene with Fe@B-A-Mo catalyst was: 20 mg of catalyst, 1 ml CCl4 as solvent and 0.4 ml TBHP as oxidant at 76 °C after 150 min. In addition recycling experiments revealed that this catalyst could be repeatedly applied for over 85% yield in epoxidation of cyclooctene for at least five cyles.
Keywords:
#Fe3O4 #Boehmite #hydrothermal #epoxidation #Cylooctene #Molybdenum hexa-carbonyl Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
Visitor: