Quantification of enhanced acid site accessibility in hierarchical zeolites - The accessibility index

被引：277

作者：

Thibault-Starzyk, Frederic ^{[2
]}

Stan, Irina ^{[2
]}

Abello, Sonia ^{[1
]}

Bonilla, Adriana ^{[1
]}

Thomas, Karine ^{[2
]}

Fernandez, Christian ^{[2
]}

Gilson, Jean-Pierre ^{[2
]}

Perez-Ramirez, Javier ^{[1
,3
]}

机构：

[1] Inst Chem Res Catalonia ICIQ, Tarragona 43007, Spain

[2] Univ Caen, ENSICAEN, Catalyse & Spectrochim Lab, CNRS, F-14050 Caen, France

[3] Passeig Lluis Co 23, Catalan Inst Res & Adv Studies ICREA, Barcelona 08010, Spain

来源：

JOURNAL OF CATALYSIS | 2009年 / 264卷 / 01期

关键词：

Accessibility index; Hierarchical zeolites; Desilication; Mesoporous crystals; Infrared spectroscopy; Alkylpyridines; Catalyst effectiveness; CATALYTIC-ACTIVITY; PROBE MOLECULES; MFI ZEOLITES; ZSM-5; DESILICATION; MECHANISM; SPECTROSCOPY; GENERATION; DIFFUSION; CRYSTALS;

D O I：

10.1016/j.jcat.2009.03.006

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

An accessibility index (ACI) was derived from infrared spectroscopy of substituted alkylpyridines with different size (pyridine: 0.57 nm, 2,6-lutidine: 0.67 nm, and 2,4,6-collidine: 0.74 nm) over hierarchical porous ZSM-5 crystals. The samples were prepared by selective silicon extraction of a commercial sample in NaOH (desilication), and they contained different degrees of intracrystalline mesoporosity. Our results demonstrate the enhanced accessibility of Bronsted acid sites in the hierarchical zeolites. For example, a relatively bulky molecule such as collidine, which probes practically no acid site of the parent medium-pore MFI structure, can access up to 40% of the acid sites in the mesoporous sample. The ACI is a powerful tool to standardize acid site accessibility in zeolites, and can be used to rank the effectiveness of synthetic strategies to prepare hierarchical zeolites. (C) 2009 Elsevier Inc. All rights reserved.

引用

页码：11 / 14

页数：4

共 27 条

[1] Perspectives of micro/mesoporous composites in catalysis
Cejka, Jiri
Mintova, Svetlana
[J]. CATALYSIS REVIEWS-SCIENCE AND ENGINEERING, 2007, 49 (04): : 457 - 509
[2] From microporous to mesoporous molecular sieve materials and their use in catalysis
Corma, A
[J]. CHEMICAL REVIEWS, 1997, 97 (06) : 2373 - 2419
[3] Corma A, 2000, ANGEW CHEM INT EDIT, V39, P1499, DOI 10.1002/(SICI)1521-3773(20000417)39:8<1499::AID-ANIE1499>3.0.CO
[4] 2-0
[5] Templating mesoporous zeolites
Egeblad, Kresten
Christensen, Christina H.
Kustova, Marina
Christensen, Claus H.
[J]. CHEMISTRY OF MATERIALS, 2008, 20 (03) : 946 - 960
[6] Evaluation of accessible acid sites on solids by 15N NMR spectroscopy with di-tert-butylpyridine as base
Farcasiu, D
Leu, R
Corma, A
[J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2002, 106 (05) : 928 - 932
[7] Acidic properties of SSZ-33 and SSZ-35 novel zeolites:: a complex infrared and MAS NMR study
Gil, Barbara
Zones, Stacey I.
Hwang, Son-Jong
Bejblova, Martina
Cejka, Jiri
[J]. JOURNAL OF PHYSICAL CHEMISTRY C, 2008, 112 (08) : 2997 - 3007
[8] Mechanism of hierarchical porosity development in MFI zeolites by desilication:: The role of aluminium as a pore-directing agent
Groen, JC
Peffer, LAA
Moulijn, JA
Pérez-Ramírez, J
[J]. CHEMISTRY-A EUROPEAN JOURNAL, 2005, 11 (17) : 4983 - 4994
[9] Pore size determination in modified micro- and mesoporous materials.: Pitfalls and limitations in gas adsorption data analysis
Groen, JC
Peffer, LAA
Pérez-Ramírez, J
[J]. MICROPOROUS AND MESOPOROUS MATERIALS, 2003, 60 (1-3) : 1 - 17
[10] Direct demonstration of enhanced diffusion in mesoporous ZSM-5 zeolite obtained via controlled desilication
Groen, Johan C.
Zhu, Weidong
Brouwer, Sander
Huynink, Steven J.
Kapteijn, Freek
Moulijn, Jacob A.
Perez-Ramirez, Javier
[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2007, 129 (02) : 355 - 360

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