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Document Type |
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Thesis |
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Document Title |
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Benzylation of benzene over insitu generated heteropolyacid catalysts on surface of nano metal phosphate بنزلة البنزين على حفازات الحمض عديد الأنوية المولد على اسطح فوسفات النانوفلز |
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Subject |
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Faculty of Sciences > Chemistry department |
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Document Language |
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Arabic |
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Abstract |
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Tethered metal-PO4 groups, such as those found in the framework of iron phosphate nanotubes (FeP) were utilized to grow the Keggin type molybdenum and tungsten heteropolyacid (HPA) clusters on the surface of FeP under acidic conditions. The interactions between the FeP surface and HPA clusters help to generate the active species during the impregnation step. Nano sized Mo-FeP and W-FeP composites with different Mo and W molar loadings (1-5%) were prepared by following the established method. The synthesized materials were characterized by elemental analysis, XRD, TEM, Raman spectroscopy, XPS, pyridine adsorption by FTIR spectroscopy for acidity measurements, N2-physisorption, H2-temperature programed reduction etc. techniques. Spectroscopic characterization results suggest that Keggin-type FeMoP species were formed on the surface of the iron phosphate nanotubes in the case of catalysts with higher (4 and 5 mol%) Mo and W loadings.
To study the role of acidity and redox properties of catalysts in benzylation reaction, the catalysts were tested for benzylation of benzene using benzyl chloride. Pure FeP nanotubes, Fe2O3, MoO3, WO3 and bulk FeMoP & FeWP HPA samples are less active than MoOx-FeP and WOx-FeP composite samples for the benzylation of benzene with benzyl chloride, MoOx-FeP catalysts showed better performance than WOx-FeP catalysts, particularly the 5 mol% Mo loaded catalyst showed high activity. The enhanced catalytic activity of MoOx-FeP catalysts attributed to the presence of easily reducible and porous FeMoP heteropolyacid species. These materials can be readily separated from the reaction system for reuse. They are resistant to leaching of the active heteropolyacid species. |
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Supervisor |
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Prof. Dr. Mohamed Mokhtar Mohamed Mostafa |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1436 AH
2015 AD |
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Co-Supervisor |
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Prof. Dr. Katabathini Narasimharao |
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Added Date |
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Thursday, December 24, 2015 |
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Researchers
| ابتسام عالي المطيري | Al-Mutairi, Ebtesam Aali | Researcher | Master | |
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