SBA-15 supported HPW: Effective catalytic performance in the alkylation of phenol

The present investigation reveals that Keggin structure of phosphotungstic acid is retained even at higher loadings in SBA-15. The 30%PW/SBA-15 material is found to possess high Bronsted acidity as evidenced from the pyridine adsorption studies. The catalytic activity of PW/SBA-15 samples in the ter...

Full description

Saved in:
Bibliographic Details
Published in:Journal of molecular catalysis. A, Chemical Chemical, 2006-12, Vol.260 (1), p.49-55
Main Authors: Kumar, G. Satish, Vishnuvarthan, M., Palanichamy, M., Murugesan, V.
Format: Article
Language:English
Subjects:
Catalysis
Chemistry
Exact sciences and technology
General and physical chemistry
Phenol
Phosphotungstic acid
PW/SBA-15
SBA-15
tert-Butylation
Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The present investigation reveals that Keggin structure of phosphotungstic acid is retained even at higher loadings in SBA-15. The 30%PW/SBA-15 material is found to possess high Bronsted acidity as evidenced from the pyridine adsorption studies. The catalytic activity of PW/SBA-15 samples in the tert-butylation of phenol illustrates that 30%PW/SBA-15 is the most active catalyst. ▪ SBA-15 was synthesized using non-ionic surfactant as the structure directing agent at 40 °C. It was then impregnated with different loadings (10, 30, 50 and 70%) of phosphotungstic acid. They were characterized by XRD, N 2 adsorption, FT-IR and DRIFT techniques. The physicochemical characterization revealed that SBA-15 could accommodate discrete phosphotungstic acid due to its large pore volume and high surface area. The catalytic activity of these materials was examined in the vapour phase tert-butylation of phenol using tert-butyl alcohol as the alkylating agent. The influence of reaction parameters such as reaction temperature, reactant feed ratio, WHSV and time on stream was studied, and the results were correlated with physicochemical characteristics of the catalysts. 4- tert-Butyl phenol was observed as the major product with high selectivity. Among the catalysts, 30% phosphotungstic acid supported SBA-15 showed high phenol conversion under optimum conditions, which is significantly higher than either phosphotungstic acid loaded mesoporous AlPO or AlMCM-41.
ISSN:1381-1169
1873-314X
DOI:10.1016/j.molcata.2006.07.050