Loading...

Synthesis of Metal-Organic Frameworks and Self-supported Coordination Polymers of Transition Metals with Catalytic Potential as Template for Supported Pd Nanoparticles and Preparation of Metal Oxide Nanoparticles for Olefin Epoxidation and C-C Coupling Reactions

Ashouri, Fatemeh | 2014

1024 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 46344 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Bagherzadeh, Mojtaba
  7. Abstract:
  8. In this research, synthesis of new heterogeneous catalysts has been studied. These catalysts were prepared in three different areas of the synthesis of coordination polymers and metal-organic frameworks, supported palladium nanoparticles on these polymers, and production of metal oxide nanoparticles. At first, metal organic frameworks of cobalt and manganese transition metals were synthesized through hydrothermal method. In order to prepare these frameworks, 1,4-benzenedicarboxylic acid (terephthalic acid) and 2-amino-1,4-benzenedicarboxylic acid ligands were utilized as spacer ligands. X-ray analysis indicated that the structure of polymers is composed of secondary building units (SBUs) of Mn-O and Co-O which have been widened to infinity. The [Mn3(1,4-BDC)3(DMF)4]n and [Co3(BDC)3(DMF)2(H2O)2]n frameworks are composed of corner shared octahedra of MnIIO6 and CoIIO6 units which are further mutually linked by benzene units from 1,4-benzendicarboxylate linkers, furnishing two-dimensional polymer. The catalytic potential of these polymers in the reaction of olefin oxidation was examined. Results indicated that these polymers were appropriate heterogeneous catalysts in olefin oxidation reaction and exhibited good stability and recyclability in these reactions.
    The synthesized coordination polymers were utilized as a template for the supported palladium nanoparticles. Palladium nanoparticles were loaded on coordination polymers of manganes-terephthalate, cobalt-terephthalate and cobalt-2-aminoterephthalate by solution impregnation method. The analyses showed that these palladium nanoparticles were located at the surface of polymers and are catalytically active species for carbon-carbon coupling reaction. In order to achieve the optimum performance of the catalyst, the carbon-carbon coupling reaction conditions in the Mizoroki-Heck reaction was studied in the presence of supported palladium nanoparticles on polymers. The catalytic cycle was suggested for these reactions based on the obtained results. Stability and recyclability are among the noteworthy properties of these catalysts.
    Meanwhile, the synthesized polymers were used as precursor for the production of metal-oxide nanoparticles. The synthesized manganese and cobalt-terephthalate polymers were calcinated at high temperature to obtain Co3O4, Mn3O4 and Mn2O3 nanoparticles after removing of organic ligands. The synthesized metal oxide nanoparticles with the average size 40-60 nm were very active catalysts in olefin oxidation reaction. The Mn3O4 and Co3O4 heterogeneous catalysts can be recycled up to four and nine successive reactions respectively, which make these nonoparticles valuable
  9. Keywords:
  10. Heterogeneous Catalysis ; Palladium Nanoparticle ; Olefins Epoxidation ; Self-Supported Coordination Polymer ; Metal-Organic Framework ; Metal Oxide Nanoparticles ; Carbon-Carbon Coupling

 Digital Object List

 Bookmark

No TOC