Publication Type Journal Article
Title Desilication of a TON zeolite with NaOH: Influence on porosity, acidity and catalytic properties
Authors P. Matias C. Sa Couto I. Graca JM Lopes; José M. Lopes Ana P. Carvalho F. Ramoa Ribeiro M. Guisnet
Groups CATHPRO
Journal APPLIED CATALYSIS A-GENERAL
Year 2011
Month May
Volume 399
Number 1
Pages 100-109
Abstract A TON zeolite (Si/Al = 31) was treated at 353 K with NaOH solutions of different concentrations C (0.05-0.4 M) and for different times t (30-300 min). The resulting samples were characterized by various techniques: SEM, XRD, nitrogen adsorption-desorption, pyridine chemisorption followed by FTIR and 1-butene isomerisation at 333 K. The filtrate analysis shows a simultaneous dissolution of Si and Al with a large preference for Si (Si/Al from 35 to 150), especially at high t and low C values. The increase with t of the filtrate Si/Al ratio was related to the redeposition of Al on the zeolite under the form of extraframework species with Lewis acidity. The alkali treatment caused the creation of mesopores with similar to 20 nm diameter, a limited decrease in the Bronsted acidity and a significant increase in the Lewis acidity. With all samples, 1-butene double bond shift selectively occurred but with a fast deactivation due to carbonaceous deposits which can be eliminated from the zeolite through nitrogen sweeping. Desilication had no effect on the catalyst stability but increased the initial activity. The activity per protonic site (TOF) was shown to be correlated with the volume of created mesopores, which shows that these mesopores facilitate the access of 1-butene molecules to the active sites. (C) 2011 Elsevier B.V. All rights reserved.
DOI http://dx.doi.org/10.1016/j.apcata.2011.03.049
ISBN
Publisher
Book Title
ISSN 0926-860X
EISSN
Conference Name
Bibtex ID ISI:000291421400013
Observations
Back to Publications List