Dissertation > Excellent graduate degree dissertation topics show

Studies on the Preparation and Catalytic Properties of Metal-Organic Frameworks Immobiled Phosphotungstic Heteropoly Acid

Author: ZhangChengJun
Tutor: YangXinLi
School: Henan University of Technology
Course: Polymer Chemistry and Physics
Keywords: Metal-organic framework Phosphotungstic acid(HPAs) Esterification Catalytic oxidation
CLC: O643.36
Type: Master's thesis
Year: 2012
Downloads: 269
Quote: 0
Read: Download Dissertation


Metal-organic frameworks (MOFs) are a novel kind of functional material with specialproperties. It has a particular pore structure and high specific surface area, which is differentfrom the traditional porous materials such as zeolite. Owing to its unique and outstandingproperties, MOFs has potential applications in catalysis field. Therefore, the study on thecatalytic performance is of significance. The main purpose of the study is to explore themetal-organic frameworks as catalyst carrier’s application value and develop some novelMOFs supported phosphotungstic acid catalysts prepared by the direct synthetic method orincipient wetness impregnation method, in which the dispersion of the active phosphotungsticacid has been improved and the interaction between the active species and the MOFs hasbeeen strengthened. In the dissertation, the influences of preparation and reaction conditionson the catalytic perfermonce have also been studied and the catalysts have been characterizedby various techniques such as XRD, TEM and BET. The main results were as follows:i) The novel HPAs/MOF-5catalyst have been prepared by the direct synthetic methodwith phosphotungstic acid (HPAs) and Metal-organic frameworks materials (MOF-5) asactive species and supports, respectively. Its catalytic performance for the esterification ofpara-hydroxybenzoic acid and propanol has been studied. The results show that the contentsof HPAs have obvious effects on the structures and catalytic performances of the catalysts andthe18.6wt.%HPAs/MOF-5catalyst shows the best catalytic activity. XRD and FT-IR resultsindicate HPAs are highly dispersed in the catalysts. The optimum reaction conditions ofpropyl p-hydroxybenzoate synthesis are that the molar ratio of alcohol to acid is4:1, thecatalyst is5%of the quality of p-hydroxy benzoic acid, the reaction time is2h, and thereaction temperature was82℃. The highest yield of propyl p-hydroxybenzoate could reach58.9%.ii) MIL-101is a kind of MOFs materials with high termal and chemical stability, whichhas both micro and mesoporous strutures. The HPAs/MIL-101catalysts are prepared by theconditional impregnation method and its catalytic activities for the selective oxidation ofcyclopentene to glutaraldehyde are reached. The optimum reaction conditions are thatphosphotungstic acid contents are30wt.%, the reaction temperature is35℃,the reactiontime is16h, tertbutyl alcohol amount is10ml, H2O2(50%) aqueous solution is1.4ml, and thecatalyst amount is0.3g. The highest yield of glutaraldehyde could reach70.6%. The reproducibility test results showed that the catalyst has a better stability and could be reusedfor two times. For the esterification, the optimal preparation conditions of HPAs/MIL-101catalyst proved that its stability was better, and could be repeated use. Using infraredspectroscopy, X-ray powder diffraction, thermal analysis, N2adsorption and transmissionelectron microscope, MIL-101and series HPAs/MIL-101were characterized. The resultsshowed that the structure of MIL-101and HPAs/MIL-101was relatively stable; HPAssupported on MIL-101was highly dispersive, distributed evenly.iii) By hydrothermal synthesis method, two kinds of metal-organic frameworksCo-MOFs (Co3(BTC)2·12H2O) and Ni-MOFs (Ni3(BTC)2·8H2O) are synthesized using Co2+and Ni2+as the metal centers respectively,1,3,5-benzentricarboxylic acid as ligand,triethylamine as deprotonation of alkali. By X-ray single crystal diffraction, elementalanalysis, infrared spectroscopy and thermogravimetric analysis method, the structure,composition and stability are analyzed of the as-synthesized frameworks. The results showthat they are of three-dimensional network structure, high purity and good stability. Twonovel kinds of catalysts were prepared after supported Phosphotungstic acids. Wepreliminarily studied the catalyst performance on the esterification reaction and selectiveoxidation of cyclopentene. The results showed that HPAs/Co-MOFs is of excellent catalyticperformance on the esterification reaction, and isoamyl acetate yield reached75.3%;HPAs/Ni-MOFs is of better catalytic performance on the selective oxidation of cyclopentene,and glutaraldehyde yield reached53.8%; XRD characterization showed that they had strongstability in the reaction system.

Related Dissertations

  1. Penicillium Expansum TS414 Lipase in Pichia Pastori: Expression, Purification and Enantioselective Esterification of (R, S)-naproxen,Q814
  2. The Biodiesel Production from Wasted Edible Oil by Two Steps Catalyzed by Resin,TE667
  3. The Study of NO Low-temperature Catalytic Oxidation Over MnFeO_x Catalyst,X701
  4. Study on the Synthesis and Properties of Poly(1,4-Cyclohexyledimethylene Terephthalate) (PCT),TQ323.4
  5. Biodiesel Production from Waste Oil and Study of Reduction of the Condensation Point,TE667
  6. Syntheses, Structures and Properties of Metal-organic Frameworks Based on Dicarboxylate Ligands,O621.13
  7. Study on Electrochemistry and Raman Spectrum of Picoline Electro-Oxidation Beavior in Non-aqueous System,O626.321
  8. Direct Oxidation of Primary Alcohols to Methyl Esters Catalyzed by Nano-Au/SBA-16 Catalyst,TQ225.241
  9. Synthesis and Performance of Itaconic Acid Series Polycarboxylate Superplasticizer,TU528.042.2
  10. Preparation and Catalytic Activity of Magnetic Heteropolyacids Catalysts,TQ426
  11. Intensification on Hydrolysis and Esterification Precess by Hydrodynamic Cavitation Technology in Biodiesel Preparation,TE667
  12. Heterogeneous Catalytic Ozone Oxidation for Pharmaceutical Wastewater Treatment,X787
  13. Electrocatalytic Oxidation of Dyes Using Cobalt Phthalocyanine Modified Activated Carbon Fiber Electrode,X791
  14. Study on the Bromolactonization of Alkenoic Acids with Hypervalent Iodion Reagent,O621.25
  15. Study on Oxidation of Organic Pollutants Catalyzed by Activated Carbon Fiber Supported Cobalt Phthalocyanine,X50
  16. Experimental Research on the Electro-catalytic Oxidation Treatment for DDNP Production Wastewater Using BDD Film Electrode,X703
  17. Researches on M-xylene Oxidation Catalyzed by Phosphotungstic Acid Loaded on Activated Carbon,TQ245.12
  18. Study on the Catalyst for the Partial Oxidation of Methane to Oxygenous Compound,TQ223.121
  19. Study on Synthesis of Poly (Trimethylene Terephthalate) with Titanium Catalyst,O643.3
  20. Esterification of Lipopeptide and Structural Characterization of the Products,TQ423.4
  21. Ethyl Acetate Production Technology Development and Application,TQ225.241

CLC: > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Chemical kinetics,catalysis > Catalytic > Catalyst
© 2012 www.DissertationTopic.Net  Mobile