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Immobilization Heavy Metal Ions and Nanoparticles (Au, Cu, Pd) on Biopolymers and Their Catalytic Activities in the Organic Reactions

Habibi, Zahra | 2019

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 51819 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Pourjavadi, Ali
  7. Abstract:
  8. Recently, biopolymers such as alginate, cellulose, chitosan, gelatine, starch and wool have been used as supports for catalytic applications. Several interesting features of the biopolymers for example, bio-degradable, environmentally safe, high sorption capacity, physical and chemical versatility make them attractive to use as supports. This study, the four functionalized biopolymer-based composites were designed and synthesized as well as heterogeneous catalysts used in the synthesis of 1,2,3-triazoles, oxidation of alcohol, reduction of nitroarenes and carbon-carbon coupling reactions.A novel cellulose supported copper NHC complex has been prepared by the reaction of cellulose supported imidazolium salt with copper(I) iodide. The catalyst is active in the synthesis of 1,2,3-triazoles via a one-pot reaction of alkyl/benzyl halides or tosylates and terminal alkynes, with sodium azide in water.A novel gold nanoparticle supported on cellulose fibers with ionic liquid framework (Au NPs@CL-IL) has been shown to be a highly active and recyclable catalyst for the oxidation of primary and secondary alcohols, and reduction of nitroarenes in aqueous media. The reusability of this catalyst is high and the catalyst can be reused ten times without a significant decrease in its catalytic activity. Furthermore, the TEM micrograph of the recovered catalyst showed the presence of well-distributed Au NPs on the CL-IL fibers without any aggregation. The porous carbon (PC) material was prepared from the carbonization of pomegranate peel waste. Subsequently, the magnetically separable Fe3O4@PC was synthesized from the Fe3O4 nanoparticles decorated on PC by the co-precipitation method of iron ions. Finally, Fe3O4@PC was successfully decorated with palladium nanoparticles in a simple route by reducing H2PdCl4 in the presence of sodium dodecyl sulfate, which is used as both a surfactant and reducing agent. Additionally, the effect of temperature on carbonization process was studied. The Pd/Fe3O4@PC nanocomposite was used as an efficient and heterogeneous catalyst for the Suzuki-Miyaura and Sonogashira cross-coupling reactions in an environmentally friendly medium.The nitrogen doped carbon (N-C) material with very high surface area (2028.4 m2g-1) was prepared from silk cocoon by carbonization with KOH activation. Subsequently, the magnetically separable Ni@N-C was synthesized from the nickel nanoparticles decorated on N-C by the chemical reduction of nickel ions. The Ni@N-C nanocomposite was used as an efficient and heterogeneous catalyst for the reduction of nitroarenes and synthesis of propargylamines in an environmentally friendly med
  9. Keywords:
  10. Biopolymer ; Nanoparticles ; Metal Ions ; Heterogeneous Catalysis ; Organic Reactions ; Heavy Metals

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