Highly active and selective AlSBA-15 catalysts for the vapor phase tert-butylation of phenol
Title | Highly active and selective AlSBA-15 catalysts for the vapor phase tert-butylation of phenol |
Publication Type | Journal Article |
Year of Publication | 2005 |
Authors | Vinu, A, Devassy, BM, Halligudi, SB, Bohlmann, W, Hartmann, M |
Journal | Applied Catalysis A-General |
Volume | 281 |
Issue | 1-2 |
Pagination | 207-213 |
Date Published | MAR |
Type of Article | Article |
ISSN | 0926-860X |
Keywords | Acidity, AlSBA-15, aluminum incorporation, butylation of phenol, SBA-15 |
Abstract | Hexagonally ordered mesoporous AISBA-15 catalysts having n(Si)/(nA]) ratios from 7 to 215 have been synthesized hydrothermally using a cheap non-ionic block copolymer as the structure-directing agent. The obtained materials were analyzed by XRD and nitrogen adsorption to determine the structural order and the textural properties. It has been observed by Al-27 MAS NMR spectroscopy that aluminum atoms are exclusively in tetrahedral coordination for all samples except AISBA-15(7), where octahedral aluminum has been detected to some extent. Temperature-programmed desorption of pyridine showed that AISBA-15(45) has a higher number of strong acid sites as compared to other mesoporous materials such as FeMCM-41, AIMCM-41 and FcAlMCM-41. The catalyst AlSBA-15(45)showed superior performance in the acid-catalyzed tertiary butylation of phenol employing tert-butanol as the alkylation agent. A high phenol conversion of 86.3% is observed for this catalyst at a reaction temperature of 150 degrees C. Over AISBA-15(45), the 4-TBP yield amounts to 40.5% and the 2,4-DTBP yield corresponds to 37.9%. (c) 2004 Elsevier B.V. All rights reserved. |
DOI | 10.1016/j.apcata.2004.11.031 |
Type of Journal (Indian or Foreign) | Foreign |
Impact Factor (IF) | 4.012 |