Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol
AlMCM-41 mesoporous molecular sieve modified by impregnation with sulphuric acid in toluene possesses only Brönsted acid sites. The catalyst exhibits a high catalytic activity for tert-butylation of phenol with high selectivity to 2,4-di-tert-butylphenol in liquid phase. 27Al MAS NMR study indicat...
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| Format: | Article |
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Elsevier B.V.
2007
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| Online Access: | http://eprints.utm.my/7316/ |
| _version_ | 1848891445219426304 |
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| author | Ng, Eng Poh Nur, Hadi Wong, Ka Lun Muhid, Mohd Nazlan Mohd Hamdan, Halimaton |
| author_facet | Ng, Eng Poh Nur, Hadi Wong, Ka Lun Muhid, Mohd Nazlan Mohd Hamdan, Halimaton |
| author_sort | Ng, Eng Poh |
| building | UTeM Institutional Repository |
| collection | Online Access |
| description | AlMCM-41 mesoporous molecular sieve modified by impregnation with sulphuric acid in toluene possesses only Brönsted acid sites. The catalyst exhibits a high catalytic activity for tert-butylation of phenol with high selectivity to 2,4-di-tert-butylphenol in liquid phase. 27Al MAS NMR study indicates that the modification of AlMCM-41 with sulphuric acid in toluene leaves only octahedrally coordinated Al species. The tetrahedrally coordinated Al species which exist before modification with sulphuric acid in toluene being dealuminated to form extraframework octahedrally coordinated Al species. The mesoporous structure of AlMCM-41 is retained after modification, but pore size decreases by ca. 3 Å by the modification. The active sites are postulated on the basis of XRD, FTIR, 27Al MAS NMR, TGA, BET analysis and FTIR-pyridine adsorption studies that -OSO3H bonded to octahedrally coordinated Al species. |
| first_indexed | 2025-11-15T20:58:05Z |
| format | Article |
| id | utm-7316 |
| institution | Universiti Teknologi Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-15T20:58:05Z |
| publishDate | 2007 |
| publisher | Elsevier B.V. |
| recordtype | eprints |
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| spelling | utm-73162017-10-23T01:48:48Z http://eprints.utm.my/7316/ Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol Ng, Eng Poh Nur, Hadi Wong, Ka Lun Muhid, Mohd Nazlan Mohd Hamdan, Halimaton QD Chemistry AlMCM-41 mesoporous molecular sieve modified by impregnation with sulphuric acid in toluene possesses only Brönsted acid sites. The catalyst exhibits a high catalytic activity for tert-butylation of phenol with high selectivity to 2,4-di-tert-butylphenol in liquid phase. 27Al MAS NMR study indicates that the modification of AlMCM-41 with sulphuric acid in toluene leaves only octahedrally coordinated Al species. The tetrahedrally coordinated Al species which exist before modification with sulphuric acid in toluene being dealuminated to form extraframework octahedrally coordinated Al species. The mesoporous structure of AlMCM-41 is retained after modification, but pore size decreases by ca. 3 Å by the modification. The active sites are postulated on the basis of XRD, FTIR, 27Al MAS NMR, TGA, BET analysis and FTIR-pyridine adsorption studies that -OSO3H bonded to octahedrally coordinated Al species. Elsevier B.V. 2007-04-30 Article PeerReviewed Ng, Eng Poh and Nur, Hadi and Wong, Ka Lun and Muhid, Mohd Nazlan Mohd and Hamdan, Halimaton (2007) Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol. Applied Catalysis A:General, 323 . pp. 58-65. ISSN 0926-860X http://dx.doi.org/10.1016/j.apcata.2007.02.001 10.1016/j.apcata.2007.02.001 |
| spellingShingle | QD Chemistry Ng, Eng Poh Nur, Hadi Wong, Ka Lun Muhid, Mohd Nazlan Mohd Hamdan, Halimaton Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol |
| title | Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol
|
| title_full | Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol
|
| title_fullStr | Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol
|
| title_full_unstemmed | Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol
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| title_short | Generation of Brönsted acidity in AlMCM-41 by sulphation for enhanced liquid phase tert-butylation of phenol
|
| title_sort | generation of broìˆnsted acidity in almcm-41 by sulphation for enhanced liquid phase tert-butylation of phenol |
| topic | QD Chemistry |
| url | http://eprints.utm.my/7316/ http://eprints.utm.my/7316/ http://eprints.utm.my/7316/ |