Journal ArticleDOI
Study of the state of aluminium in zeolite-β
Elodie Bourgeat-Lami,Pascale Massiani,Francesco Di Renzo,Pierre Espiau,François Fajula,Thierry Des Courieres +5 more
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TLDR
In this article, the modifications of the state of aluminium when introducing protons into zeolite-β have been investigated by combining several analytical techniques, and it was concluded that the octahedrally coordinated and NMR invisible aluminium must be regarded as inherent parts of the framework of the Zeolite and their formation is explained by a distortion of aluminic sites caused by the high electron affinity of the proton.About:
This article is published in Applied Catalysis.The article was published on 1991-05-02. It has received 291 citations till now. The article focuses on the topics: Aluminium & Pyridine.read more
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Effects of hydrothermal aging on NH3-SCR reaction over Cu/zeolites
TL;DR: In this article, the effects of hydrothermal treatment on model Cu/zeolite catalysts were investigated to better understand the nature of Cu species for the selective catalytic reduction of NO{sub x} by NH{sub 3}.
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Characterization of nanocrystalline zeolite Beta
TL;DR: In this article, a thorough characterization of zeolite Beta materials with crystal sizes in the 200 to 10nm range has been done by using a combination of physicochemical techniques (N 2 adsorption, XRD, multinuclear MAS NMR, pyridine adaption, FTIR, thermal analysis).
Journal ArticleDOI
Perspectives of Micro/Mesoporous Composites in Catalysis
Jiří Čejka,Svetlana Mintova +1 more
TL;DR: In this paper, the recent development in the field of synthesis, characterization and particularly catalytic investigation of zeolite-based materials combining micro and mesoporous features is discussed, and the relevance of individual experimental techniques for analysis of the composites, i.e., their structure, porosity, chemical composition, morphological features, and so on, are described.
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Stepwise Dealumination of Zeolite Βeta at Specific T-Sites Observed with 27Al MAS and 27Al MQ MAS NMR
TL;DR: Using 27Al MAS and 27Al MQ MAS NMR, dealumination of zeolite H-Beta has been observed at specific T-positions in the framework as mentioned in this paper.
Journal ArticleDOI
Current Understanding of Cu-Exchanged Chabazite Molecular Sieves for Use as Commercial Diesel Engine DeNOx Catalysts
TL;DR: In this paper, the authors summarized the recent progress of selective catalytic reduction (SCR) of NOx with ammonia using metal-exchanged molecular sieves with a chabazite structure has been commercialized on diesel vehicles.
References
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Journal ArticleDOI
High-resolution aluminum-27 NMR of aluminosilicates
E. Lippmaa,Ago Samoson,M. Magi +2 more
TL;DR: In this paper, the first and second coordination spheres and the Al-O-Si bond angles were used to determine isotropic chemical shifts of quadrupolar nuclei in solids.
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The framework topology of zeolite beta
John B. Higgins,R.B. LaPierre,John L. Schlenker,A.C. Rohrman,J.D. Wood,G.T. Kerr,W.J. Rohrbaugh +6 more
TL;DR: The proposed framework structures are consistent with the known diffraction, sorption, and cation-exchange properties of zeolite beta.
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Two new three-dimensional twelve-ring zeolite frameworks of which zeolite beta is a disordered intergrowth
Michael Treacy,John M. Newsam +1 more
TL;DR: The structure of zeolite beta has been determined by high-resolution electron microscopy, electron diffraction and computer assisted modeling as discussed by the authors, showing that it is an intergrown hybrid of two distinct but closely related structures.
Journal Article
The framework topology of zeolite beta
John B. Higgins,R.B. LaPierre,John L. Schlenker,A.C. Rohrman,J.D. Wood,G.T. Kerr,W.J. Rohrbaugh +6 more
TL;DR: The tetrahedral framework structure of zeolite beta is disordered along (001) planes as mentioned in this paper, and the disordered structure is related by a/3 and/or b/3 displacements on (1) planes to three ordered polytype structures with triclinic, monoclinic and tetragonal symmetry.
Journal ArticleDOI
Crystallization mechanism of zeolite beta from (TEA)2O, Na2O and K2O containing aluminosilicate gels.
TL;DR: In this paper, a detailed chemical analysis of intermediate solid and liquid phases obtained from a large number of gel compositions at different synthesis times as well as SEM and XRD investigations of the solids allow to determine the crystallization mechanism.