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Titolo:
Change in pore structure of MFI zeolite by treatment with NaOH aqueous solution
Autore:
Suzuki, T; Okuhara, T;
Indirizzi:
Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 0600810, Japan Hokkaido Univ Sapporo Hokkaido Japan 0600810 oro, Hokkaido 0600810, Japan
Titolo Testata:
MICROPOROUS AND MESOPOROUS MATERIALS
fascicolo: 1, volume: 43, anno: 2001,
pagine: 83 - 89
SICI:
1387-1811(200103)43:1<83:CIPSOM>2.0.ZU;2-C
Fonte:
ISI
Lingua:
ENG
Soggetto:
ARGON POROSIMETRY; CATALYSIS; HYDROGEN; REMOVAL; ZSM-5; ACID;
Keywords:
MFI zeolite; NaOH-treatment; micropores; supermicropores; external surface area;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
14
Recensione:
Indirizzi per estratti:
Indirizzo: Okuhara, T Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 0600810, Japan Hokkaido Univ Sapporo Hokkaido Japan 0600810 do 0600810, Japan
Citazione:
T. Suzuki e T. Okuhara, "Change in pore structure of MFI zeolite by treatment with NaOH aqueous solution", MICROP M M, 43(1), 2001, pp. 83-89

Abstract

Changes of the pore size and the pore volume of MFI zeolite (Si/Al = 37) upon treatment with an NaOH aqueous solution (0.05 mol dm(-3)) have been investigated at the temperature range from 323 to 343 K by means of adsorptions of Ar and N-2. The total surface area (BET surface area) increased at theinitial stage of the treatment and then decreased slowly. The change of the total surface area was attributed to that of the external surface area. BJH analysis of the N-2 adsorption isotherm revealed that the supermicropores having a width of about 1.8 nm were created by the treatment of NaOH. In addition, Saito-Foley analysis of the Ar adsorption isotherm showed that the size and the volume of the micropores remained almost unchanged after theNaOH-treatment. It was evident from elemental analysis that about 30% Si of the MFT zeolite was dissolved by the treatment, while only a few percent of Al was released. These results demonstrate that the framework of the crystalline phase was stable against the NaOH-treatment and probably the amorphous phases present at the boundary of the crystallites dissolved to form the supermicropores, supporting a previous report [Chem. Lett. (2000) 882]. (C) 2001 Elsevier Science B.V. All rights reserved.

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Documento generato il 19/01/20 alle ore 09:11:51