%0 Journal Article %J Applied Catalysis A-General %D 2005 %T Highly active and selective AlSBA-15 catalysts for the vapor phase tert-butylation of phenol %A Vinu, A. %A Devassy, Biju M. %A Halligudi, Shivaraj B. %A Bohlmann, W. %A Hartmann, Martin %K Acidity %K AlSBA-15 %K aluminum incorporation %K butylation of phenol %K SBA-15 %X

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.

%B Applied Catalysis A-General %I ELSEVIER SCIENCE BV %C PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS %V 281 %P 207-213 %8 MAR %G eng %N 1-2 %9 Article %3 Foreign %4 4.012 %R 10.1016/j.apcata.2004.11.031