Isomorphous Substitution of Si for Al, Ga, Fe, In and B in Molecular Sieves of MFI Structure. A Quantum Chemical, Ammonia Desorption and Catalytic Activity Study of Framework Si-OH-M Acid Site Strength

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Title:Isomorphous Substitution of Si for Al, Ga, Fe, In and B in Molecular Sieves of MFI Structure. A Quantum Chemical, Ammonia Desorption and Catalytic Activity Study of Framework Si-OH-M Acid Site Strength
Creators:
Zahradník, Rudolf
Hobza, Pavel
Wichterlová, Blanka
Čejka, Jiří
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 58, 10, pp. 2474-2488

Abstract

A theoretical and experimental study of metallosilicates with MFI structure revealed the order Al &gt; Ga &gt; Fe &gt; In &gt; B in the acid Si-OH-M framework site strength. <i>Ab initio</i> calculations of the energy and geometry characteristics in a simple structural unit modelling the isomorphous substitution were carried out for Al, Ga, In and B as heteroatoms in silicates. Experimental data on toluene alkylation with ethylene and temperature-programmed desorption of ammonia allowed to distinguish the acid site strength of Al-, Fe- and In-silicates, thus, completing the acidity sequence of metallosilicates synthesized so far. Moreover, the study confirmed rather short-range effects resulting from isomorphous substitution of a heteroatom into the molecular sieve framework.

Title:Isomorphous Substitution of Si for Al, Ga, Fe, In and B in Molecular Sieves of MFI Structure. A Quantum Chemical, Ammonia Desorption and Catalytic Activity Study of Framework Si-OH-M Acid Site Strength
Creators:
Zahradník, Rudolf
Hobza, Pavel
Wichterlová, Blanka
Čejka, Jiří
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:58
Number:10
Page Range:pp. 2474-2488
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19932474UNSPECIFIED
ID Code:364
Item Type:Article
Deposited On:06 Feb 2009 17:00
Last Modified:06 Feb 2009 16:00

Citation

Zahradník, Rudolf; Hobza, Pavel; Wichterlová, Blanka; Čejka, Jiří (1993) Isomorphous Substitution of Si for Al, Ga, Fe, In and B in Molecular Sieves of MFI Structure. A Quantum Chemical, Ammonia Desorption and Catalytic Activity Study of Framework Si-OH-M Acid Site Strength. Collection of Czechoslovak Chemical Communications, 58 (10). pp. 2474-2488. ISSN 0010-0765

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