Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares
Autor(a) principal: | |
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Data de Publicação: | 2016 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/8848 |
Resumo: | Nanosized NaX zeolites (FAU) (crystallite size = 16 nm; Si/Al ratio = 1,5) were synthesized and modified through ion exchange with linear alkylammonium cations containing from one to six carbons, with the intent to activate basic sites. In this work, commercial microsized zeolites (Aldrich) were also ion exchanged for comparison matters and all samples were characterized. Scanning electron microscopy analysis showed that both micro- and nanosized zeolites containing sodium portray polycrystalline particles: the former presents octahedral habit and particle size of 2952 nm and the latter presents an indefinite habit and particle size of 426 nm. Among the ion exchanged samples, none presented complete exchange of the Na+ cations due to steric hindrance. Nanosized zeolites presented higher exchange degrees than the microsized ones, which is due to higher accessibility to the exchange sites. Such factors also explain the exchange degrees’ reduction with the cations’ chain length, which is less abrupt among the nanosized samples. This happens due to the nanosized samples’ higher interparticular porosity, which has also allowed their micropore volumes’ constant decrease, differently from the microsized samples, which faced a minimum value with butylammonium. When the cations’ length is increased, the unit cell expands in comparison to the zeolites containing sodium since bulkier cations cause variations in the length and angle of the of the O-Si-O and O-Al-O bonds. Through thermogravimetric analysis in oxidant atmosphere, it was observed that the longer the carbon chain length, the lower is the mass loss, which evidences the lower diffusional limitations. The same was observed in inert atmosphere, which indicates that the presence of O2 does not influence the thermal events. Nanosized zeolites illustrate smoother mass loss profiles, which marks smaller diffusional limitations. The zeolitic materials were catalytically evaluated along the Knoevenagel condensation between butyraldehyde and ethyl cyanoacetate (3% m/m catalyst) during 1 h. The nanometric zeolites presented higher conversions and higher reaction rates when t = 0 than the microcrystalline ones, confirming the advantages of nanosized materials. |
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Motta, Ingrid LopesCardoso, Dilsonhttp://lattes.cnpq.br/2462847535959232http://lattes.cnpq.br/73167164219847028f3ee6cf-7337-4a23-8cfd-7121d7304cae2017-06-13T12:43:30Z2017-06-13T12:43:30Z2016-02-15MOTTA, Ingrid Lopes. Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares. 2016. Dissertação (Mestrado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8848.https://repositorio.ufscar.br/handle/ufscar/8848Nanosized NaX zeolites (FAU) (crystallite size = 16 nm; Si/Al ratio = 1,5) were synthesized and modified through ion exchange with linear alkylammonium cations containing from one to six carbons, with the intent to activate basic sites. In this work, commercial microsized zeolites (Aldrich) were also ion exchanged for comparison matters and all samples were characterized. Scanning electron microscopy analysis showed that both micro- and nanosized zeolites containing sodium portray polycrystalline particles: the former presents octahedral habit and particle size of 2952 nm and the latter presents an indefinite habit and particle size of 426 nm. Among the ion exchanged samples, none presented complete exchange of the Na+ cations due to steric hindrance. Nanosized zeolites presented higher exchange degrees than the microsized ones, which is due to higher accessibility to the exchange sites. Such factors also explain the exchange degrees’ reduction with the cations’ chain length, which is less abrupt among the nanosized samples. This happens due to the nanosized samples’ higher interparticular porosity, which has also allowed their micropore volumes’ constant decrease, differently from the microsized samples, which faced a minimum value with butylammonium. When the cations’ length is increased, the unit cell expands in comparison to the zeolites containing sodium since bulkier cations cause variations in the length and angle of the of the O-Si-O and O-Al-O bonds. Through thermogravimetric analysis in oxidant atmosphere, it was observed that the longer the carbon chain length, the lower is the mass loss, which evidences the lower diffusional limitations. The same was observed in inert atmosphere, which indicates that the presence of O2 does not influence the thermal events. Nanosized zeolites illustrate smoother mass loss profiles, which marks smaller diffusional limitations. The zeolitic materials were catalytically evaluated along the Knoevenagel condensation between butyraldehyde and ethyl cyanoacetate (3% m/m catalyst) during 1 h. The nanometric zeolites presented higher conversions and higher reaction rates when t = 0 than the microcrystalline ones, confirming the advantages of nanosized materials.Zeólitas NaX (FAU) de cristais nanométricos (diâmetro de cristalito de 16 nm; razão molar Si/Al de 1,5) foram sintetizadas e modificadas através de troca iônica com cátions alquilamônio lineares de um a seis carbonos para a ativação de sítios básicos. No trabalho, efetuou-se também a troca iônica com zeólitas de cristais micrométricos (Aldrich) para fins de comparação, caracterizando-se todas as amostras. Por MEV, observou-se que as zeólitas sódicas micro- e nanométricas possuem partículas policristalinas, apresentando as primeiras hábito octaédrico e diâmetro de partícula de 2952 nm e, as últimas, hábito indefinido e diâmetro de 426 nm. Dentre as zeólitas trocadas, nenhuma apresentou troca completa dos cátions Na+ devido a impedimentos estéricos. As zeólitas nanométricas apresentaram graus de troca superiores aos das micrométricas devido à maior acessibilidade aos sítios de troca. Tais fatores também justificam a redução do grau de troca com o aumento do comprimento do cátion de compensação, sendo essa redução muito mais suave entre as amostras nanométricas. Isto ocorre devido à maior porosidade interparticular das zeólitas nanométricas, a qual permitiu que os volumes de microporos dessas zeólitas fossem sempre decrescentes, diferentemente das amostras micrométricas que atingiram um valor mínimo com o cátion butilamônio. Aumentando-se o comprimento do cátion, observa-se a expansão da cela unitária em comparação às zeólitas com cátion sódio pois cátions mais volumosos provocam variações no comprimento e nos ângulos das ligações O-Si-O e O-Al-O. Por análise termogravimétrica em atmosfera oxidante, observou-se que as zeólitas nanométricas exibem perfis de decomposição muito mais suaves, evidenciando as menores limitações difusionais. O mesmo foi observado em atmosfera inerte, indicando que a presença do O2 não influencia os eventos térmicos. Os materiais zeolíticos foram avaliados cataliticamente através da reação de condensação de Knoevenagel entre butiraldeído e cianoacetato de etila (3% m/m de catalisador) por 1 h. As zeólitas nanométricas apresentaram maiores conversões e maiores velocidades de reação no tempo zero que as microcristalinas, confirmando-se as vantagens de materiais com dimensões nanométricas.Não recebi financiamentoporUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Engenharia Química - PPGEQUFSCarZeólitaFaujasitaPropriedades básicasCátions alquilamônio linearesCondensação de KnoevenagelCristal nanométricoZeoliteFaujasiteBasic propertiesLinear alkylammonium cationsKnoevenagel condensationNanometric particleENGENHARIAS::ENGENHARIA QUIMICAPropriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio linearesinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisOnline60060045193456-2aac-47ce-8120-3995d1ca2a46info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALDissILM.pdfDissILM.pdfapplication/pdf5724691https://repositorio.ufscar.br/bitstream/ufscar/8848/1/DissILM.pdf47011a82c00569e1418ba50a076d335cMD51LICENSElicense.txtlicense.txttext/plain; charset=utf-81957https://repositorio.ufscar.br/bitstream/ufscar/8848/2/license.txtae0398b6f8b235e40ad82cba6c50031dMD52TEXTDissILM.pdf.txtDissILM.pdf.txtExtracted texttext/plain341779https://repositorio.ufscar.br/bitstream/ufscar/8848/3/DissILM.pdf.txt7eecc0da8544bed637e491842292319eMD53THUMBNAILDissILM.pdf.jpgDissILM.pdf.jpgIM Thumbnailimage/jpeg6955https://repositorio.ufscar.br/bitstream/ufscar/8848/4/DissILM.pdf.jpg022b98d9ab80ae791a8114b74ff4197dMD54ufscar/88482023-09-18 18:31:24.734oai:repositorio.ufscar.br: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Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:31:24Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares |
title |
Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares |
spellingShingle |
Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares Motta, Ingrid Lopes Zeólita Faujasita Propriedades básicas Cátions alquilamônio lineares Condensação de Knoevenagel Cristal nanométrico Zeolite Faujasite Basic properties Linear alkylammonium cations Knoevenagel condensation Nanometric particle ENGENHARIAS::ENGENHARIA QUIMICA |
title_short |
Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares |
title_full |
Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares |
title_fullStr |
Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares |
title_full_unstemmed |
Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares |
title_sort |
Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares |
author |
Motta, Ingrid Lopes |
author_facet |
Motta, Ingrid Lopes |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/7316716421984702 |
dc.contributor.author.fl_str_mv |
Motta, Ingrid Lopes |
dc.contributor.advisor1.fl_str_mv |
Cardoso, Dilson |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/2462847535959232 |
dc.contributor.authorID.fl_str_mv |
8f3ee6cf-7337-4a23-8cfd-7121d7304cae |
contributor_str_mv |
Cardoso, Dilson |
dc.subject.por.fl_str_mv |
Zeólita Faujasita Propriedades básicas Cátions alquilamônio lineares Condensação de Knoevenagel Cristal nanométrico |
topic |
Zeólita Faujasita Propriedades básicas Cátions alquilamônio lineares Condensação de Knoevenagel Cristal nanométrico Zeolite Faujasite Basic properties Linear alkylammonium cations Knoevenagel condensation Nanometric particle ENGENHARIAS::ENGENHARIA QUIMICA |
dc.subject.eng.fl_str_mv |
Zeolite Faujasite Basic properties Linear alkylammonium cations Knoevenagel condensation Nanometric particle |
dc.subject.cnpq.fl_str_mv |
ENGENHARIAS::ENGENHARIA QUIMICA |
description |
Nanosized NaX zeolites (FAU) (crystallite size = 16 nm; Si/Al ratio = 1,5) were synthesized and modified through ion exchange with linear alkylammonium cations containing from one to six carbons, with the intent to activate basic sites. In this work, commercial microsized zeolites (Aldrich) were also ion exchanged for comparison matters and all samples were characterized. Scanning electron microscopy analysis showed that both micro- and nanosized zeolites containing sodium portray polycrystalline particles: the former presents octahedral habit and particle size of 2952 nm and the latter presents an indefinite habit and particle size of 426 nm. Among the ion exchanged samples, none presented complete exchange of the Na+ cations due to steric hindrance. Nanosized zeolites presented higher exchange degrees than the microsized ones, which is due to higher accessibility to the exchange sites. Such factors also explain the exchange degrees’ reduction with the cations’ chain length, which is less abrupt among the nanosized samples. This happens due to the nanosized samples’ higher interparticular porosity, which has also allowed their micropore volumes’ constant decrease, differently from the microsized samples, which faced a minimum value with butylammonium. When the cations’ length is increased, the unit cell expands in comparison to the zeolites containing sodium since bulkier cations cause variations in the length and angle of the of the O-Si-O and O-Al-O bonds. Through thermogravimetric analysis in oxidant atmosphere, it was observed that the longer the carbon chain length, the lower is the mass loss, which evidences the lower diffusional limitations. The same was observed in inert atmosphere, which indicates that the presence of O2 does not influence the thermal events. Nanosized zeolites illustrate smoother mass loss profiles, which marks smaller diffusional limitations. The zeolitic materials were catalytically evaluated along the Knoevenagel condensation between butyraldehyde and ethyl cyanoacetate (3% m/m catalyst) during 1 h. The nanometric zeolites presented higher conversions and higher reaction rates when t = 0 than the microcrystalline ones, confirming the advantages of nanosized materials. |
publishDate |
2016 |
dc.date.issued.fl_str_mv |
2016-02-15 |
dc.date.accessioned.fl_str_mv |
2017-06-13T12:43:30Z |
dc.date.available.fl_str_mv |
2017-06-13T12:43:30Z |
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info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
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masterThesis |
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publishedVersion |
dc.identifier.citation.fl_str_mv |
MOTTA, Ingrid Lopes. Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares. 2016. Dissertação (Mestrado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8848. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/8848 |
identifier_str_mv |
MOTTA, Ingrid Lopes. Propriedades de zeólitas x formadas por partículas micro- e nanométricas contendo cátions alquilamônio lineares. 2016. Dissertação (Mestrado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8848. |
url |
https://repositorio.ufscar.br/handle/ufscar/8848 |
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openAccess |
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Universidade Federal de São Carlos Câmpus São Carlos |
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Programa de Pós-Graduação em Engenharia Química - PPGEQ |
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UFSCar |
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Universidade Federal de São Carlos Câmpus São Carlos |
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