Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts

With increasing legislative demands to remove nitrogen oxides (NOx) from automotive diesel exhaust, new catalyst systems are investigated and intensely studied in industry as well in academia. The most prevailing catalytic method of choice is the selective catalytic reduction (SCR) where non-toxic u...

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Autor: VENNESTROM, PETER NICOLAI RAVNBORG
Tipo de recurso: tesis doctoral
Fecha de publicación:2014
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/43217
Acceso en línea:https://riunet.upv.es/handle/10251/43217
Access Level:acceso abierto
Palabra clave:Heterogeneous catalysis
Zeolites
DeNOx
Cu-exchange
Selective catalytic reduction
QUIMICA ORGANICA
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oai_identifier_str oai:riunet.upv.es:10251/43217
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network_name_str España
repository_id_str
dc.title.none.fl_str_mv Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts
title Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts
spellingShingle Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts
VENNESTROM, PETER NICOLAI RAVNBORG
Heterogeneous catalysis
Zeolites
DeNOx
Cu-exchange
Selective catalytic reduction
QUIMICA ORGANICA
title_short Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts
title_full Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts
title_fullStr Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts
title_full_unstemmed Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts
title_sort Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts
dc.creator.none.fl_str_mv VENNESTROM, PETER NICOLAI RAVNBORG
author VENNESTROM, PETER NICOLAI RAVNBORG
author_facet VENNESTROM, PETER NICOLAI RAVNBORG
author_role author
dc.contributor.none.fl_str_mv Corma Canós, Avelino
Kustov, Arkady
Instituto Universitario Mixto de Tecnología Química
Repositorio Institucional de la Universitat Politècnica de València Riunet
dc.subject.none.fl_str_mv Heterogeneous catalysis
Zeolites
DeNOx
Cu-exchange
Selective catalytic reduction
QUIMICA ORGANICA
topic Heterogeneous catalysis
Zeolites
DeNOx
Cu-exchange
Selective catalytic reduction
QUIMICA ORGANICA
description With increasing legislative demands to remove nitrogen oxides (NOx) from automotive diesel exhaust, new catalyst systems are investigated and intensely studied in industry as well in academia. The most prevailing catalytic method of choice is the selective catalytic reduction (SCR) where non-toxic urea is used as a reductant for practical reasons. Usually urea is stored in a separate tank and once injected into the exhaust system it hydrolyses into the more aggressive reductant NH3 and CO2. 4 NH3 + 4 NO + O2 -> 4 N2 + 6 H2O (NH3-SCR reaction) In regions where vanadium is not banned cost effective V2O5/WO3/TiO2 NH3-SCR catalyst systems can be used. Vanadium based are well understood, but they do however not provide stability above ca. 550 °C for longer periods of time. In exhaust treatment systems where the temperature is either high or where high temperature excursions are experienced from e.g. regeneration of particulate filters, zeolite based catalysts are therefore today the most promising candidates as high-temperature stable and non-toxic catalysts for the NH3-SCR reaction. Among the most promising candidates are the Cu- and Fe-based zeolites. Usually Fe based zeolites show good performance in the temperature range 250-500 °C and reasonable stability, whereas Cu-based zeolites show good low-temperature activity in the 180-400 °C range. The presence of copper does however also lead to a lower stability of the catalyst material. Since the low-temperature activity is of paramount importance it is necessary to improve this behavior. Therefore the purpose of this project is to investigate: - The deactivation mechanism of copper based zeolites - The influence of the zeolite framework on stability and activity These investigations should mostly be carried out on model systems such as Cu-ZSM-5 and Cu-IM-5. Recently it was found that zeolite materials with the CHA-type structure show increased hydrothermal stability, most likely originating from the small 8-MR window openings in the structure. Part of the project should therefore also include investigations on this type and other similar structures, and therefore entail: - Synthesis, in-depth characterization and catalytic testing of Cu-SSZ-13 and Cu-SAPO-34 (both structures having the CHA-type framework) - Theoretical DFT calculations on relevant parameters found by the in-depth investigation of the afore-mentioned materials - Synthesis and testing of similar materials with 8-MR windows to elucidate the influence of the zeolite sub-structure i.e. if different ring sizes in the structure influences the catalytic performance Relevant characterization techniques include, besides conventional methods, in situ methods such as: high resolution (transmission) electron microscopy, infrared (and raman) spectroscopy together with X-ray absorption spectroscopy. These are all techniques that will complement each other to produce invaluable results. Zeolites are today applied in many and diverse applications both within automotive and environmental catalysis, but also within the petrochemical and renewable chemistry. The findings of this project are therefore also believed to contribute to a more comprehensive understanding of this class of materials, relevant to many areas of heterogeneous catalysis, and therefore have the potential, to create research and business with very high impact.
publishDate 2014
dc.date.none.fl_str_mv 2014
2014-10-14
2014
2014-09-25
dc.type.none.fl_str_mv doctoral thesis
http://purl.org/coar/resource_type/c_db06
AM
http://purl.org/coar/version/c_ab4af688f83e57aa
dc.type.openaire.fl_str_mv info:eu-repo/semantics/doctoralThesis
format doctoralThesis
dc.identifier.none.fl_str_mv https://riunet.upv.es/handle/10251/43217
url https://riunet.upv.es/handle/10251/43217
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
Reserva de todos los derechos
http://rightsstatements.org/vocab/InC/1.0/
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
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Reserva de todos los derechos
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eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Universitat Politècnica de València
publisher.none.fl_str_mv Universitat Politècnica de València
dc.source.none.fl_str_mv reponame:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
instname:Universitat Politècnica de València (UPV)
instname_str Universitat Politècnica de València (UPV)
reponame_str RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
collection RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
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spelling Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalystsVENNESTROM, PETER NICOLAI RAVNBORGHeterogeneous catalysisZeolitesDeNOxCu-exchangeSelective catalytic reductionQUIMICA ORGANICAWith increasing legislative demands to remove nitrogen oxides (NOx) from automotive diesel exhaust, new catalyst systems are investigated and intensely studied in industry as well in academia. The most prevailing catalytic method of choice is the selective catalytic reduction (SCR) where non-toxic urea is used as a reductant for practical reasons. Usually urea is stored in a separate tank and once injected into the exhaust system it hydrolyses into the more aggressive reductant NH3 and CO2. 4 NH3 + 4 NO + O2 -> 4 N2 + 6 H2O (NH3-SCR reaction) In regions where vanadium is not banned cost effective V2O5/WO3/TiO2 NH3-SCR catalyst systems can be used. Vanadium based are well understood, but they do however not provide stability above ca. 550 °C for longer periods of time. In exhaust treatment systems where the temperature is either high or where high temperature excursions are experienced from e.g. regeneration of particulate filters, zeolite based catalysts are therefore today the most promising candidates as high-temperature stable and non-toxic catalysts for the NH3-SCR reaction. Among the most promising candidates are the Cu- and Fe-based zeolites. Usually Fe based zeolites show good performance in the temperature range 250-500 °C and reasonable stability, whereas Cu-based zeolites show good low-temperature activity in the 180-400 °C range. The presence of copper does however also lead to a lower stability of the catalyst material. Since the low-temperature activity is of paramount importance it is necessary to improve this behavior. Therefore the purpose of this project is to investigate: - The deactivation mechanism of copper based zeolites - The influence of the zeolite framework on stability and activity These investigations should mostly be carried out on model systems such as Cu-ZSM-5 and Cu-IM-5. Recently it was found that zeolite materials with the CHA-type structure show increased hydrothermal stability, most likely originating from the small 8-MR window openings in the structure. Part of the project should therefore also include investigations on this type and other similar structures, and therefore entail: - Synthesis, in-depth characterization and catalytic testing of Cu-SSZ-13 and Cu-SAPO-34 (both structures having the CHA-type framework) - Theoretical DFT calculations on relevant parameters found by the in-depth investigation of the afore-mentioned materials - Synthesis and testing of similar materials with 8-MR windows to elucidate the influence of the zeolite sub-structure i.e. if different ring sizes in the structure influences the catalytic performance Relevant characterization techniques include, besides conventional methods, in situ methods such as: high resolution (transmission) electron microscopy, infrared (and raman) spectroscopy together with X-ray absorption spectroscopy. These are all techniques that will complement each other to produce invaluable results. Zeolites are today applied in many and diverse applications both within automotive and environmental catalysis, but also within the petrochemical and renewable chemistry. The findings of this project are therefore also believed to contribute to a more comprehensive understanding of this class of materials, relevant to many areas of heterogeneous catalysis, and therefore have the potential, to create research and business with very high impact.Universitat Politècnica de ValènciaCorma Canós, AvelinoKustov, ArkadyInstituto Universitario Mixto de Tecnología QuímicaRepositorio Institucional de la Universitat Politècnica de València Riunet20142014-10-1420142014-09-25doctoral thesishttp://purl.org/coar/resource_type/c_db06AMhttp://purl.org/coar/version/c_ab4af688f83e57aainfo:eu-repo/semantics/doctoralThesisapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttps://riunet.upv.es/handle/10251/43217reponame:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valénciainstname:Universitat Politècnica de València (UPV)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2Reserva de todos los derechoshttp://rightsstatements.org/vocab/InC/1.0/info:eu-repo/semantics/openAccessoai:riunet.upv.es:10251/432172026-06-13T07:49:27Z
score 15,300724

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