Synthesis of nanosized ZSM-2 zeolite with potential acid catalytic properties

Covarrubias, C; Quijada, R; Rojas, R.

Abstract

Nanosized ZSM-2 zeolite crystals (~100 nm) with suitable surface acid properties were prepared. ZSM-2 zeolite forms with improved acidity were obtained through thermal deammoniation and steam treatment. Detailed characterization of acidic ZSM-2 zeolite was carried out by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance infrared Fourier transform (DRIFT), nitrogen sorptometry, dynamic light scattering (DLS), thermogravimetry (TGA), potentiometric acidity measurements, and FTIR analysis of pyridine adsorption. Acid properties of ZSM-2 zeolite were significantly improved by conversion into its protonated (H-ZSM-2) and dealuminated (DEAL-ZSM-2) forms, in which bridged Si(OH)Al groups with Brönsted acidity (H-ZSM-2) and aluminium extraframework species with Lewis acid character (DEAL-ZSM-2) are generated. These acidic ZSM-2 zeolite forms also maintain adequate crystalline order and high surface area values, making this nanosized zeolite attractive for catalytic applications. In the context of catalyst supporting materials for the polymerization of olefins, the DEAL-ZSM-2 zeolite form showed Lewis acid properties similar to those of a traditional MAO-modified silica support. Thus, DEAL-ZSM-2 zeolite appears as a promising material to be evaluated as polymerization catalyst support when a reduction of the amount of high-cost MAO cocatalyst is desired. © 2008 Elsevier Inc. All rights reserved.

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Título según WOS: Synthesis of nanosized ZSM-2 zeolite with potential acid catalytic properties
Título según SCOPUS: Synthesis of nanosized ZSM-2 zeolite with potential acid catalytic properties
Título de la Revista: MICROPOROUS AND MESOPOROUS MATERIALS
Volumen: 117
Número: 01-feb
Editorial: Elsevier
Fecha de publicación: 2009
Página de inicio: 118
Página final: 125
Idioma: English
URL: http://linkinghub.elsevier.com/retrieve/pii/S1387181108003041
DOI:

10.1016/j.micromeso.2008.06.013

Notas: ISI, SCOPUS