Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658315
Title: Synthesis and catalytic applications of ruthenium- and iron-based nanoparticles from the pyrolysis of metal-containing homopolymers and block copolymers
Author: Erhard, Felix Maria Maximilian
Awarding Body: University of Bristol
Current Institution: University of Bristol
Date of Award: 2012
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Abstract:
This Thesis is concerned with the synthesis of new Fe- and Rucontaining homopolymers and block copolymers and their applications as precursors for the fabrication of catalytically active nanoparticles upon pyrolysis (NPs). The strained sila[l]ferrocenophane (T]-CSH4) Fe(T]-CsH4)SiMeRc has been synthesised. Two different routes for its synthesis Were employed and compared. The compound was polymerised via thermal ringopening polymerisation (ROP), which afforded insoluble polymeric material. Photo controlled ROP. was used to afford narrowly dispersed, high molecular . weight (Mn between 10,000 and 53,000 Da) air and moisture stable [(T]CsH4) Fe(T]-CsH4)-SiMeRc]n. Electrochemical characterisation of (T]-CsH4)Fe(T]CsH4)- SiMeRc revealed unusual, concentration dependent behaviour associated with the pendant Rc substituent. We postulate a dimerisation pathway based on Ru-Ru bond formation upon oxidation of the Rc side . groups. The synthesis of the block copolymer PSm-b-[(T]-CsH4)Fe(T]-CsH4)SiMeRc] n was carried out and afforded narrowly dispersed block copolymers of high molecular weight (Mn between 28,000 and 36,000 Da). The synthesis of Fe(T]-CsH4)zSi(Me)(C=CSiMe3) and its photocontrolled polymerisation to yield high molecular weight (Mn between 13,000 and 45,500 Da) [Fe(T]-CsH4)zSi(Me)(C=CSiMe3)]n is also presented. Deprotection and clusterisation with RU3(CO)12 yielded the highly metalen, riched compound [Fe( T]-CsH4)zSiCH3{(Il-H)Ru3(CO)9Cz}]n. UV -irradiation was utilised for cross-linking reactions, which proceeded readily. The block copolymers PSm-h-[Fe(T]-CsH4)zSi(Me)(C=CSiMe3)]n and PSm~h-[Fe(T]CsH4) zSiCH3{(Il-H)Ru3(CO)9CZ}]n were prepared. The fabrication of metal-containing nanoparticles (NPs) via pyrolysis of the metallopolymers was carried out via bulk' and thin film pyrolysis between 500 and 1000°C. Analysis of the resulting materials revealed the formation of RuSi, RuzFeSi, RU4Fe and/or Ru NPs, depending on the material and pyrolysis temperature. The particles were embedded in a carbonaceous matrix. The catalytic activity towards hydrogenation of cyclohexene by the particles formed via pyrolysis of thin films was investigated and showed some catalytic activity. The synthesis of a metallopolymer for the fabrication of monometallic Ru NPs is also discussed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.658315  DOI: Not available
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