Shape-selective catalysis by phosphate modified ZSM-5: Generation of new acid sites with pore narrowing

Janardhan, H L and Shanbhag, G V and Halgeri, A B (2014) Shape-selective catalysis by phosphate modified ZSM-5: Generation of new acid sites with pore narrowing. Applied Catalysis A: General, 471. pp. 12-18.

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Abstract

tPore narrowing of ZSM-5 was carried out by phosphate modification technique and shape selectivitywas evaluated for alkylation, disproportionation reactions and competitive reaction of ethylbenzene andmeta-xylene. Catalysts were characterized by XRD, FTIR, MAS NMR, NH3-TPD, PZC etc. Post synthesismodification of ZSM-5 by phosphate treatment generated new kinds of acid sites with pore narrow-ing. Even though there was a change in acid site strength, these active sites efficiently catalyzed toluenealkylation with methanol, ethylbenzene alkylation with ethanol and disproportionation of ethylbenzene.These active sites formed monolayer islands over catalyst surface and narrowed the pore opening result-ing in high para-selectivity. Decrease in pore volume by phosphate modification has a direct correlationwith increase in shape selectivity. Constraint index for modified catalysts obtained from competitivereaction of ethylbenzene and m-xylene was used to determine extent of pore narrowing by phosphatemodification.

Item Type: Article
Uncontrolled Keywords: Phosphate modification Shape selectivity Zeolite Alkylation Vapor phase Catalyst ZSM-5a
Subjects: Research > Research Center - Technical
Depositing User: MIT Library
Date Deposited: 28 Jun 2016 14:47
Last Modified: 28 Jun 2016 14:47
URI: http://eprints.manipal.edu/id/eprint/146423

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