Center for Molecular Modeling - A. Nollet

The effect of confined space on the growth of naphthalenic species in an H-SSZ-13 catalyst: a molecular modeling study

wim — Thu, 08 Dec 2011 14:31:05 +0000

K. Hemelsoet, A. Nollet, M. Vandichel, D. Lesthaeghe, V. Van Speybroeck, M. Waroquier

ChemCatChem

1 (3), 373-378

2009

Abstract

Methylation reactions of naphthalenic species over the acidic microporous zeolite with chabazite topology have been investigated by means of two-layered ab initio computations. Large cluster results combined with van der Waals contributions provide thermodynamic and kinetic results of successive methylation steps. The growth of fused bicyclic species is important as these can act as hydrocarbon pool species within the methanol-to-olefin (MTO) process, but ultimately leads to the deactivation of the catalyst. The influence of the confined space of the zeolite pore on the resulting transition state or product shape selectivity is investigated in detail.

DOI

http://dx.doi.org/10.1002/cctc.200900208

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09 chemcatchem 1(3)373 hemelsoet.pdf

09 cover picture 1(3).pdf

Theoretical simulations elucidate the role of naphthalenic species during methanol conversion within H-SAPO-34

wim — Thu, 08 Sep 2011 08:19:15 +0000

K. Hemelsoet, A. Nollet, V. Van Speybroeck, M. Waroquier

Chemistry - A European Journal

17(3) 9083–9093

2011

Abstract

The role of naphthalenic species during the methanol-to-olefins (MTO) process in a silicoaluminophosphate zeolitic material exhibiting the chabazite topology (H-SAPO-34) has been studied from first principles. These species could either act as active olefin-eliminating compounds or as precursors for deactivating species. Results incorporating van der Waals contributions for finite large clusters point out that successive methylation steps of naphthalenic compounds are feasible. The calculated intrinsic activation barrier is relatively independent of the number of methyl groups already attached on the aromatic compound and is approximately 140 kJ mol(-1) . The influence of the composition of the catalyst and hence the acidic strength on the intrinsic chemical kinetics was investigated in detail through comparison with the isostructural high-silicon material. Apparent chemical kinetics, starting from adsorbed methanol on the acid site, were also computed. The initiation steps of the side-chain route starting from a trimethylated naphthalenium ion were also examined. The actual side-chain methylation exhibits a high barrier and hence this mechanism involving methylated naphthalenes is not expected to be an active ethene-eliminating route in H-SAPO-34.

DOI

http://dx.doi.org/10.1002/chem.201100920

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11 chem eur j 17, 9083 hemelsoet.pdf

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Naphthalene derivatives in the MTO process from a molecular modeling perspective: reactive species or coke?

wim — Tue, 18 Oct 2011 07:08:56 +0000

A. Nollet, K. Hemelsoet, D. Lesthaeghe, V. Van Speybroeck, M. Waroquier

Poster

Conference / event / venue

Xth Netherlands' Catalysis and Chemistry Conference (NCCC X)

Noordwijkerhout, The Netherlands

Monday, 2 March, 2009 to Wednesday, 4 March, 2009

Abstract

n3c-x-Nollet09.pdf

Growth of naphthalenic HP species: influence of the CHA topology from a molecular modeling perspective

wim — Tue, 18 Oct 2011 07:03:34 +0000

K. Hemelsoet, A. Nollet, D. Lesthaeghe, V. Van Speybroeck, M. Waroquier

Poster

Conference / event / venue

inGAP NANOCAT Summerschool 2009

Trondheim, Norway

Sunday, 21 June, 2009 to Friday, 26 June, 2009

Abstract

09 INGAP_KarenHemelsoet.pdf

Growth of naphthalenic HP species: influence of the CHA topology from a molecular modeling perspective

wim — Mon, 17 Oct 2011 14:12:25 +0000

K. Hemelsoet, A. Nollet, D. Lesthaeghe, V. Van Speybroeck, M. Waroquier

Poster

Conference / event / venue

Quantum Chemistry in Belgium 9th edition

Louvain-la-Neuve, Belgium

Tuesday, 26 January, 2010

Abstract

2010 HQCB9 emelsoet_Karen.pdf

Growth of naphthalenic HP species: influence of the CHA topology from a molecular perspective

wim — Mon, 17 Oct 2011 09:58:56 +0000

K. Hemelsoet, A. Nollet, D. Lesthaeghe, V. Van Speybroeck, M. Waroquier

Talk

Conference / event / venue

InGAP NANOCAT Summerschool

Trondheim, Norway

Sunday, 21 June, 2009 to Friday, 26 June, 2009

Abstract

09 INGAP_KarenHemelsoet.pdf

Ab initio study of the growth of fused bicyclic species within a zeolite-type catalyst: the influence of confinement and material composition

wim — Mon, 17 Oct 2011 08:48:53 +0000

K. Hemelsoet, A. Nollet, V. Van Speybroeck, M. Waroquier

691-692

ISBN: 9788889976296

Talk

Conference / event / venue

IZC-IMMS 2010

Sorrento, Italy

Sunday, 4 July, 2010 to Friday, 9 July, 2010

Abstract

IZC 2010 18-Hemelsoet.pdf

Conference reference

IZC-IMMS 2010

Arno Nollet

wim — Thu, 25 Aug 2011 12:32:19 +0000

Ab initio studie naar het gedrag van naftaleenderivaten in het MTO-proces: reactieve species of cokes?

wim — Wed, 24 Aug 2011 13:01:15 +0000

A. Nollet

Master of Science in Chemical Engineering

2009

Supervisors

Prof. Dr. ir. Veronique Van Speybroeck, Prof. Dr. Michel Waroquier