Desilication of a TON zeolite with NaOH: Influence on porosity, acidity and catalytic properties

P. Matias; C. Sá Couto; I. Graa; J. M. Lopes; A. P. Carvalho; F. Ramôa Ribeiro; M. Guisnet

doi:10.1016/j.apcata.2011.03.049

Desilication of a TON zeolite with NaOH: Influence on porosity, acidity and catalytic properties

P. Matias, C. Sá Couto, I. Graa, J. M. Lopes, A. P. Carvalho, F. Ramôa Ribeiro^*, M. Guisnet

^*Corresponding author for this work

Engineering

Research output: Contribution to journal › Article › peer-review

47 Citations (Scopus)

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 extra framework species with Lewis acidity. The alkali treatment caused the creation of mesopores with ∼20 nm diameter, a limited decrease in the Brønsted 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.

Original language	English
Pages (from-to)	100-109
Number of pages	10
Journal	Applied Catalysis A: General
Volume	399
Issue number	1-2
Early online date	1 Apr 2011
DOIs	https://doi.org/10.1016/j.apcata.2011.03.049
Publication status	Published - 31 May 2011

Bibliographical note

Acknowledgments
P. Matias (SFRH/BPD/48959/2008) and I. Graça (SFRH/BD/37270/2007) thank the Fundação para a Ciência e a Tecnologia (FCT) and C. Sá Couto thanks the Instituto Superior Técnico (IST-BL 319-2009) for the financial supports. The authors gratefully acknowledge the Fundação para a Ciência e a Tecnologia (FCT) for the project TON PTDC/EQU-ERQ/100317/2008, Prof. Teresa Duarte from Instituto Superior Técnico for the access to XRD facility (CONC-REEQ/670/2001), Dr. Auguste Fernandes from Instituto Superior Técnico for the XRD experiments and also Dr. Patrick Magnoux and Jean-Dominique Comparot from the University of Poitiers (France) for the infrared spectroscopy experiments.

Keywords

1-Butene isomerisation
Acidity
Desilication
Mesopore
TON zeolite

Access to Document

10.1016/j.apcata.2011.03.049

Cite this

@article{29819a69fe0c42fb92a8d606819b7adc,

title = "Desilication of a TON zeolite with NaOH: Influence on porosity, acidity and catalytic properties",

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 extra framework species with Lewis acidity. The alkali treatment caused the creation of mesopores with ∼20 nm diameter, a limited decrease in the Br{\o}nsted 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.",

keywords = "1-Butene isomerisation, Acidity, Desilication, Mesopore, TON zeolite",

author = "P. Matias and {S{\'a} Couto}, C. and I. Graa and Lopes, {J. M.} and Carvalho, {A. P.} and {Ram{\^o}a Ribeiro}, F. and M. Guisnet",

note = "Acknowledgments P. Matias (SFRH/BPD/48959/2008) and I. Gra{\c c}a (SFRH/BD/37270/2007) thank the Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia (FCT) and C. S{\'a} Couto thanks the Instituto Superior T{\'e}cnico (IST-BL 319-2009) for the financial supports. The authors gratefully acknowledge the Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia (FCT) for the project TON PTDC/EQU-ERQ/100317/2008, Prof. Teresa Duarte from Instituto Superior T{\'e}cnico for the access to XRD facility (CONC-REEQ/670/2001), Dr. Auguste Fernandes from Instituto Superior T{\'e}cnico for the XRD experiments and also Dr. Patrick Magnoux and Jean-Dominique Comparot from the University of Poitiers (France) for the infrared spectroscopy experiments.",

year = "2011",

month = may,

day = "31",

doi = "10.1016/j.apcata.2011.03.049",

language = "English",

volume = "399",

pages = "100--109",

journal = "Applied Catalysis A: General",

issn = "0926-860X",

publisher = "Elsevier",

number = "1-2",

}

TY - JOUR

T1 - Desilication of a TON zeolite with NaOH

T2 - Influence on porosity, acidity and catalytic properties

AU - Matias, P.

AU - Sá Couto, C.

AU - Graa, I.

AU - Lopes, J. M.

AU - Carvalho, A. P.

AU - Ramôa Ribeiro, F.

AU - Guisnet, M.

N1 - Acknowledgments P. Matias (SFRH/BPD/48959/2008) and I. Graça (SFRH/BD/37270/2007) thank the Fundação para a Ciência e a Tecnologia (FCT) and C. Sá Couto thanks the Instituto Superior Técnico (IST-BL 319-2009) for the financial supports. The authors gratefully acknowledge the Fundação para a Ciência e a Tecnologia (FCT) for the project TON PTDC/EQU-ERQ/100317/2008, Prof. Teresa Duarte from Instituto Superior Técnico for the access to XRD facility (CONC-REEQ/670/2001), Dr. Auguste Fernandes from Instituto Superior Técnico for the XRD experiments and also Dr. Patrick Magnoux and Jean-Dominique Comparot from the University of Poitiers (France) for the infrared spectroscopy experiments.

PY - 2011/5/31

Y1 - 2011/5/31

N2 - 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 extra framework species with Lewis acidity. The alkali treatment caused the creation of mesopores with ∼20 nm diameter, a limited decrease in the Brønsted 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.

AB - 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 extra framework species with Lewis acidity. The alkali treatment caused the creation of mesopores with ∼20 nm diameter, a limited decrease in the Brønsted 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.

KW - 1-Butene isomerisation

KW - Acidity

KW - Desilication

KW - Mesopore

KW - TON zeolite

UR - http://www.scopus.com/inward/record.url?scp=79956008985&partnerID=8YFLogxK

U2 - 10.1016/j.apcata.2011.03.049

DO - 10.1016/j.apcata.2011.03.049

M3 - Article

AN - SCOPUS:79956008985

SN - 0926-860X

VL - 399

SP - 100

EP - 109

JO - Applied Catalysis A: General

JF - Applied Catalysis A: General

IS - 1-2

ER -

Desilication of a TON zeolite with NaOH: Influence on porosity, acidity and catalytic properties

Abstract

Bibliographical note

Keywords

Access to Document

Other files and links

Fingerprint

Cite this