Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene

Mesoporous molecular sieve Al-MCM-41 with Si/Al=20 and polymethacrylic acid (PMAA) were used as supports for the immobilization of bulky iron(III)- 5,10,15,20-tetra-(4-pyridyl) porphyrin (Fe-TPyP). Metalloporphyrin of Fe(III) was encapsulated inside the mesopores of the ordered structure of Al-MCM-4...

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Main Author:	Hamid, Helda
Format:	Thesis
Language:	English
Published:	2005
Subjects:	QD Chemistry
Online Access:	http://eprints.utm.my/id/eprint/4174/1/HeldaHamidMFS2005.pdf
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spelling	my-utm-ep.41742018-01-15T07:03:45Z Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene 2005-09 Hamid, Helda QD Chemistry Mesoporous molecular sieve Al-MCM-41 with Si/Al=20 and polymethacrylic acid (PMAA) were used as supports for the immobilization of bulky iron(III)- 5,10,15,20-tetra-(4-pyridyl) porphyrin (Fe-TPyP). Metalloporphyrin of Fe(III) was encapsulated inside the mesopores of the ordered structure of Al-MCM-41 by sequential synthesis of Fe-TPyP via treatment of FeCl3 with 5,10,15,20-tetra-(4- pyridyl) porphyrin (TPyP), followed by encapsulation of Fe-TPyP. Fe-TPyP complexes were also successfully encapsulated into PMAA by polymerizing methacrylic acid (MAA) with a cross-linker around the Fe-TPyP complexes. The materials obtained were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Ultraviolet Visible Diffuse Reflectance (UV-Vis DR), Electron Spin Resonance (ESR), Luminescence and 13C CP/MAS NMR spectroscopies, Thermogravimetric Analysis (TGA) and elemental analysis. The powder XRD data confirmed that the ordered structure of mesoporous Al-MCM-41 remained intact after encapsulation process. Characterization of Fe-TPyP composite with Al-MCM-41 and PMAA using FTIR, UV-Vis DR and ESR confirmed that the structure of Fe-TPyP in inorganic and polymer supports is similar with bare Fe-TPyP. The specific interaction of Fe-TPyP in Al-MCM-41 and/or PMAA was studied by ESR, 13C CP/MAS NMR and Luminescence spectroscopies. The ESR spectra of Fe-TPyP/Al-MCM-41 and Fe-TPyP/PMAA composites showed that there is a shift towards a higher g-value confirming the interaction between Fe-TPyP and supports is occurred. By quenching of the luminescence spectra of Fe-TPyP/PMAA with various concentration of Fe-TPyP, it is evidenced that there is some interaction between Fe-TPyP and PMAA. Further evidence of interaction was corroborated by 13C CP/MAS NMR spectra with show that the peak of carboxyl of PMAA is shifted to higher magnetic field. Single-point BET surface area analysis was used to determine specific surface area of the composites. It is revealed that the surface area of Fe-TPyP/Al-MCM-41 composites is decreased with an increase in Fe-TPyP, suggesting the encapsulation of the complex in the pores of Al-MCM-41 has been achieved. With mesoporous molecular sieve (Al-MCM-41) and the polymer (PMAA) as supports, the immobilized iron-porphyrin system has demonstrated excellent activity for the single-step synthesis of phenol from benzene under mild reaction conditions. The effect of reaction time, solvent, amount of Fe-TPyP loading, temperature and the performance of the recovered catalysts have been studied. The immobilized iron-porphyrin in PMAA (Fe-TPyP/PMAA) gives a higher activity compared to Fe-TPyP supported on Al-MCM-41 (Fe-TPyP/Al-MCM-41). However, the product selectivity of Fe-TPyP/PMAA is not as good as that of Fe-TPyP/ Al-MCM-41. Thus, it is reasonable to assume that the hydrophobic nature of Fe-TPyP/PMAA would account for the high activity, while the rigid, ordered structure of Fe-TPyP/Al-MCM-41 would contribute towards the high selectivity in the single-step synthesis of phenol from benzene in the present study. 2005-09 Thesis http://eprints.utm.my/id/eprint/4174/ http://eprints.utm.my/id/eprint/4174/1/HeldaHamidMFS2005.pdf application/pdf en public masters Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	QD Chemistry
spellingShingle	QD Chemistry Hamid, Helda Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene
description	Mesoporous molecular sieve Al-MCM-41 with Si/Al=20 and polymethacrylic acid (PMAA) were used as supports for the immobilization of bulky iron(III)- 5,10,15,20-tetra-(4-pyridyl) porphyrin (Fe-TPyP). Metalloporphyrin of Fe(III) was encapsulated inside the mesopores of the ordered structure of Al-MCM-41 by sequential synthesis of Fe-TPyP via treatment of FeCl3 with 5,10,15,20-tetra-(4- pyridyl) porphyrin (TPyP), followed by encapsulation of Fe-TPyP. Fe-TPyP complexes were also successfully encapsulated into PMAA by polymerizing methacrylic acid (MAA) with a cross-linker around the Fe-TPyP complexes. The materials obtained were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Ultraviolet Visible Diffuse Reflectance (UV-Vis DR), Electron Spin Resonance (ESR), Luminescence and 13C CP/MAS NMR spectroscopies, Thermogravimetric Analysis (TGA) and elemental analysis. The powder XRD data confirmed that the ordered structure of mesoporous Al-MCM-41 remained intact after encapsulation process. Characterization of Fe-TPyP composite with Al-MCM-41 and PMAA using FTIR, UV-Vis DR and ESR confirmed that the structure of Fe-TPyP in inorganic and polymer supports is similar with bare Fe-TPyP. The specific interaction of Fe-TPyP in Al-MCM-41 and/or PMAA was studied by ESR, 13C CP/MAS NMR and Luminescence spectroscopies. The ESR spectra of Fe-TPyP/Al-MCM-41 and Fe-TPyP/PMAA composites showed that there is a shift towards a higher g-value confirming the interaction between Fe-TPyP and supports is occurred. By quenching of the luminescence spectra of Fe-TPyP/PMAA with various concentration of Fe-TPyP, it is evidenced that there is some interaction between Fe-TPyP and PMAA. Further evidence of interaction was corroborated by 13C CP/MAS NMR spectra with show that the peak of carboxyl of PMAA is shifted to higher magnetic field. Single-point BET surface area analysis was used to determine specific surface area of the composites. It is revealed that the surface area of Fe-TPyP/Al-MCM-41 composites is decreased with an increase in Fe-TPyP, suggesting the encapsulation of the complex in the pores of Al-MCM-41 has been achieved. With mesoporous molecular sieve (Al-MCM-41) and the polymer (PMAA) as supports, the immobilized iron-porphyrin system has demonstrated excellent activity for the single-step synthesis of phenol from benzene under mild reaction conditions. The effect of reaction time, solvent, amount of Fe-TPyP loading, temperature and the performance of the recovered catalysts have been studied. The immobilized iron-porphyrin in PMAA (Fe-TPyP/PMAA) gives a higher activity compared to Fe-TPyP supported on Al-MCM-41 (Fe-TPyP/Al-MCM-41). However, the product selectivity of Fe-TPyP/PMAA is not as good as that of Fe-TPyP/ Al-MCM-41. Thus, it is reasonable to assume that the hydrophobic nature of Fe-TPyP/PMAA would account for the high activity, while the rigid, ordered structure of Fe-TPyP/Al-MCM-41 would contribute towards the high selectivity in the single-step synthesis of phenol from benzene in the present study.
format	Thesis
qualification_level	Master's degree
author	Hamid, Helda
author_facet	Hamid, Helda
author_sort	Hamid, Helda
title	Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene
title_short	Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene
title_full	Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene
title_fullStr	Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene
title_full_unstemmed	Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene
title_sort	iron(iii)-porphyrin immobilized on mesoporous a1-mcm-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene
granting_institution	Universiti Teknologi Malaysia, Faculty of Science
granting_department	Faculty of Science
publishDate	2005
url	http://eprints.utm.my/id/eprint/4174/1/HeldaHamidMFS2005.pdf
_version_	1747814496884228096

Iron(III)-porphyrin immobilized on mesoporous A1-MCM-41 and polymethacrylic acid as catalysts for the single-step synthesis of phenol from benzene

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