Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno
Autor(a) principal: | |
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Data de Publicação: | 2010 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFG |
Texto Completo: | http://repositorio.bc.ufg.br/tede/handle/tde/1068 |
Resumo: | In this work were synthesized catalysts supported on activated carbons, which were obtained by carbonization of a polymer matrix. The precursor of activated carbon was the sulfonated styrene-divinylbenzene copolymer, which was synthesized by suspension polymerization in the presence of inert diluents to produce a macroporous network structure. The chemical modification was performed by sulfonation with concentrated sulfuric acid in the presence of dichloroethane. The supported catalysts were obtained by two routes. In the first one oxides were co-precipitated on the modified copolymer, and then the polymer was subjected to heat treatment and carbonization followed by activation. In the second route, the copolymer was first carbonized and subjected to activation, and then oxides were produced by co-precipitation of metalic ions. In both cases the coprecipitation involved two steps: incorporation of iron and cobalt ions through an ion exchange process and then coprecipitation in alkaline and oxidizer medium. The heat treatment consists of a heating step at 250 ° C in air atmosphere, carbonization at 900 ° C under nitrogen atmosphere and activation at 900 º C with a flow of nitrogen saturated with water vapor. The influence of the percentage of cobalt relative to iron in the material properties as well as catalytic activity in the reaction of dehydrogenation of ethylbenzene was investigated. The materials were characterized by their magnetism, infrared spectroscopy, X-ray diffraction, chemical analysis, Mossbauer spectroscopy, optical microscopy, measurements of porosity by nitrogen adsorption and catalytic activity in the reaction of catalytic dehydrogenation of ethylbenzene with water vapor. It was observed that the materials prepared by the two different routes have properties quite different as the amount of metal incorporated, the formation of oxides and textural properties. It was observed that the thermal treatments influence dramatically in the oxidation state of iron due to various reactions of oxidation and reduction occurring during the stages of synthesis and catalytic evaluation. The catalysts obtained by the two routes had better textural properties than the commercial catalyst. All supported catalysts obtained were active in the reaction of dehydrogenation of ethylbenzene. Even the support of activated carbon oxidized with nitric acid showed catalytic activity. Among the catalysts synthesized, those obtained by the second route had the best conjugated results of conversion and selectivity for the reaction, especially those synthesized with oxidized activated carbon. These catalysts are the most promising due their textural properties and surface functional groups of activated carbon. |
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RABELO, Denilsonhttp://lattes.cnpq.br/4961539278604455http://lattes.cnpq.br/2897572127546287OTTO, Carlos Rangel Neves2014-07-29T15:12:50Z2010-06-242010-02-09OTTO, Carlos Rangel Neves. Preparation, characterization and evaluation of iron oxides and cobalt supported on activated carbon and polymeric catalysts for the dehydrogenation of ethylbenzene. 2010. 117 f. Dissertação (Mestrado em Educação em Química) - Universidade Federal de Goiás, Goiânia, 2010.http://repositorio.bc.ufg.br/tede/handle/tde/1068ark:/38995/0013000009pxgIn this work were synthesized catalysts supported on activated carbons, which were obtained by carbonization of a polymer matrix. The precursor of activated carbon was the sulfonated styrene-divinylbenzene copolymer, which was synthesized by suspension polymerization in the presence of inert diluents to produce a macroporous network structure. The chemical modification was performed by sulfonation with concentrated sulfuric acid in the presence of dichloroethane. The supported catalysts were obtained by two routes. In the first one oxides were co-precipitated on the modified copolymer, and then the polymer was subjected to heat treatment and carbonization followed by activation. In the second route, the copolymer was first carbonized and subjected to activation, and then oxides were produced by co-precipitation of metalic ions. In both cases the coprecipitation involved two steps: incorporation of iron and cobalt ions through an ion exchange process and then coprecipitation in alkaline and oxidizer medium. The heat treatment consists of a heating step at 250 ° C in air atmosphere, carbonization at 900 ° C under nitrogen atmosphere and activation at 900 º C with a flow of nitrogen saturated with water vapor. The influence of the percentage of cobalt relative to iron in the material properties as well as catalytic activity in the reaction of dehydrogenation of ethylbenzene was investigated. The materials were characterized by their magnetism, infrared spectroscopy, X-ray diffraction, chemical analysis, Mossbauer spectroscopy, optical microscopy, measurements of porosity by nitrogen adsorption and catalytic activity in the reaction of catalytic dehydrogenation of ethylbenzene with water vapor. It was observed that the materials prepared by the two different routes have properties quite different as the amount of metal incorporated, the formation of oxides and textural properties. It was observed that the thermal treatments influence dramatically in the oxidation state of iron due to various reactions of oxidation and reduction occurring during the stages of synthesis and catalytic evaluation. The catalysts obtained by the two routes had better textural properties than the commercial catalyst. All supported catalysts obtained were active in the reaction of dehydrogenation of ethylbenzene. Even the support of activated carbon oxidized with nitric acid showed catalytic activity. Among the catalysts synthesized, those obtained by the second route had the best conjugated results of conversion and selectivity for the reaction, especially those synthesized with oxidized activated carbon. These catalysts are the most promising due their textural properties and surface functional groups of activated carbon.Neste trabalho foram sintetizados catalisadores suportados em carvões ativados, que foram obtidos por meio da carbonização de uma matriz polimérica. O precursor do carvão ativado foi o copolímero de estireno e divinilbenzeno sulfonado, que foi sintetizado por meio de polimerização em suspensão, na presença de diluentes inertes para a produção de uma estrutura macroporosa e reticulada. A modificação química por sulfonação foi realizada com ácido sulfúrico concentrado na presença de dicloroetano. Os catalisadores suportados foram obtidos por duas rotas. Na primeira delas os óxidos foram coprecipitados sobre o copolímero modificado, e em seguida o polímero foi submetido a tratamentos térmicos e carbonização, e posterior ativação. Na segunda rota, o copolímero foi primeiramente carbonizado e submetido a ativação, e em seguida os óxidos foram produzidos pela coprecipitação de íons metálicos. Em ambos os casos a coprecipitação envolveu duas etapas: incorporação dos íons ferro e cobalto por meio do processo de troca iônica e em seguida coprecipitação em meio alcalino oxidante. O tratamento térmico consiste em uma etapa de aquecimento a 250 ºC em atmosfera de ar, a carbonização a 900 ºC em atmosfera de nitrogênio e a ativação a 900 ºC com um fluxo de nitrogênio saturado com vapor de água. Investigou-se durante a preparação dos catalisadores a influência do percentual de cobalto em relação ao ferro nas propriedades do material, e consequentemente em sua atividade catalítica na reação de desidrogenação do etilbenzeno. Os materiais foram caracterizados por seu magnetismo, espectroscopia de infravermelho, difração de raios X, análise química, espectroscopia de Mössbauer, microscopia ótica, medidas de porosidade por adsorção física de nitrogênio e atividade catalítica na reação de desidrogenação catalítica do etilbenzeno com vapor de água. Observou-se que os materiais preparados pelas duas rotas distintas apresentaram propriedades bastante diferentes quanto a quantidade de metal incorporado/coprecipitado, a formação dos óxidos e as propriedades texturais. Evidenciou-se ainda que os tratamentos térmicos influenciam drasticamente nos óxidos formados devido a várias reações de oxidação e redução que ocorrem durante as etapas de síntese e mesmo na avaliação catalítica. Os catalisadores obtidos pelas duas rotas apresentaram propriedades texturais superiores as do catalisador comercial. Todos os catalisadores suportados obtidos foram ativos na reação de desidrogenação do etilbenzeno. Até mesmo o suporte de carvão ativado oxidado com ácido nítrico apresentou atividade catalítica. Dentre os catalisadores sintetizados, os obtidos pela segunda rota apresentaram os melhores resultados conjuntos de conversão e seletividade para a reação, principalmente os sintetizados com carvão ativado oxidado. Esses catalisadores são os mais promissores devido as propriedades texturais e aos grupos funcionais superficiais do carvão ativado.Made available in DSpace on 2014-07-29T15:12:50Z (GMT). No. of bitstreams: 1 carlos rangel.pdf: 2728067 bytes, checksum: fb16fe4d020ade6680388acadc30184b (MD5) Previous issue date: 2010-02-09application/pdfhttp://repositorio.bc.ufg.br/TEDE/retrieve/3736/carlos%20rangel.pdf.jpgporUniversidade Federal de GoiásMestrado em QuímicaUFGBREducação em QuímicaCatalisadorCarvão ativadoEtilbenzeno1. Carvão ativado 2. Catalisadores 3. Etilbenzeno desidrogenaçãoCatalystActivated carbonEthylbenzeneCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICAPreparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzenoPreparation, characterization and evaluation of iron oxides and cobalt supported on activated carbon and polymeric catalysts for the dehydrogenation of ethylbenzeneinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFGinstname:Universidade Federal de Goiás (UFG)instacron:UFGORIGINALcarlos rangel.pdfapplication/pdf2728067http://repositorio.bc.ufg.br/tede/bitstreams/1216e407-0fc6-4387-85b4-838b8e40604a/downloadfb16fe4d020ade6680388acadc30184bMD51TEXTcarlos rangel.pdf.txtcarlos rangel.pdf.txtExtracted Texttext/plain157295http://repositorio.bc.ufg.br/tede/bitstreams/d5bb10f0-f707-4ae5-ab24-64aaae256b46/download682b47bf417f74e8d54d19b6789f4835MD52THUMBNAILcarlos rangel.pdf.jpgcarlos rangel.pdf.jpgGenerated Thumbnailimage/jpeg3292http://repositorio.bc.ufg.br/tede/bitstreams/470531df-f9eb-4395-a05b-b0ec56e08429/download11855583bb5f5390b6d0c832ebcef5e9MD53tde/10682014-07-30 03:07:41.903open.accessoai:repositorio.bc.ufg.br:tde/1068http://repositorio.bc.ufg.br/tedeRepositório InstitucionalPUBhttp://repositorio.bc.ufg.br/oai/requesttasesdissertacoes.bc@ufg.bropendoar:2014-07-30T06:07:41Repositório Institucional da UFG - Universidade Federal de Goiás (UFG)false |
dc.title.por.fl_str_mv |
Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno |
dc.title.alternative.eng.fl_str_mv |
Preparation, characterization and evaluation of iron oxides and cobalt supported on activated carbon and polymeric catalysts for the dehydrogenation of ethylbenzene |
title |
Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno |
spellingShingle |
Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno OTTO, Carlos Rangel Neves Catalisador Carvão ativado Etilbenzeno 1. Carvão ativado 2. Catalisadores 3. Etilbenzeno desidrogenação Catalyst Activated carbon Ethylbenzene CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno |
title_full |
Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno |
title_fullStr |
Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno |
title_full_unstemmed |
Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno |
title_sort |
Preparação, caracterização e avaliação de óxidos de ferro e cobalto suportados em carvão ativado polimérico como catalisador na reação de desidrogenação do etilbenzeno |
author |
OTTO, Carlos Rangel Neves |
author_facet |
OTTO, Carlos Rangel Neves |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
RABELO, Denilson |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/4961539278604455 |
dc.contributor.authorLattes.fl_str_mv |
http://lattes.cnpq.br/2897572127546287 |
dc.contributor.author.fl_str_mv |
OTTO, Carlos Rangel Neves |
contributor_str_mv |
RABELO, Denilson |
dc.subject.por.fl_str_mv |
Catalisador Carvão ativado Etilbenzeno 1. Carvão ativado 2. Catalisadores 3. Etilbenzeno desidrogenação |
topic |
Catalisador Carvão ativado Etilbenzeno 1. Carvão ativado 2. Catalisadores 3. Etilbenzeno desidrogenação Catalyst Activated carbon Ethylbenzene CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
dc.subject.eng.fl_str_mv |
Catalyst Activated carbon Ethylbenzene |
dc.subject.cnpq.fl_str_mv |
CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
In this work were synthesized catalysts supported on activated carbons, which were obtained by carbonization of a polymer matrix. The precursor of activated carbon was the sulfonated styrene-divinylbenzene copolymer, which was synthesized by suspension polymerization in the presence of inert diluents to produce a macroporous network structure. The chemical modification was performed by sulfonation with concentrated sulfuric acid in the presence of dichloroethane. The supported catalysts were obtained by two routes. In the first one oxides were co-precipitated on the modified copolymer, and then the polymer was subjected to heat treatment and carbonization followed by activation. In the second route, the copolymer was first carbonized and subjected to activation, and then oxides were produced by co-precipitation of metalic ions. In both cases the coprecipitation involved two steps: incorporation of iron and cobalt ions through an ion exchange process and then coprecipitation in alkaline and oxidizer medium. The heat treatment consists of a heating step at 250 ° C in air atmosphere, carbonization at 900 ° C under nitrogen atmosphere and activation at 900 º C with a flow of nitrogen saturated with water vapor. The influence of the percentage of cobalt relative to iron in the material properties as well as catalytic activity in the reaction of dehydrogenation of ethylbenzene was investigated. The materials were characterized by their magnetism, infrared spectroscopy, X-ray diffraction, chemical analysis, Mossbauer spectroscopy, optical microscopy, measurements of porosity by nitrogen adsorption and catalytic activity in the reaction of catalytic dehydrogenation of ethylbenzene with water vapor. It was observed that the materials prepared by the two different routes have properties quite different as the amount of metal incorporated, the formation of oxides and textural properties. It was observed that the thermal treatments influence dramatically in the oxidation state of iron due to various reactions of oxidation and reduction occurring during the stages of synthesis and catalytic evaluation. The catalysts obtained by the two routes had better textural properties than the commercial catalyst. All supported catalysts obtained were active in the reaction of dehydrogenation of ethylbenzene. Even the support of activated carbon oxidized with nitric acid showed catalytic activity. Among the catalysts synthesized, those obtained by the second route had the best conjugated results of conversion and selectivity for the reaction, especially those synthesized with oxidized activated carbon. These catalysts are the most promising due their textural properties and surface functional groups of activated carbon. |
publishDate |
2010 |
dc.date.available.fl_str_mv |
2010-06-24 |
dc.date.issued.fl_str_mv |
2010-02-09 |
dc.date.accessioned.fl_str_mv |
2014-07-29T15:12:50Z |
dc.type.status.fl_str_mv |
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 |
OTTO, Carlos Rangel Neves. Preparation, characterization and evaluation of iron oxides and cobalt supported on activated carbon and polymeric catalysts for the dehydrogenation of ethylbenzene. 2010. 117 f. Dissertação (Mestrado em Educação em Química) - Universidade Federal de Goiás, Goiânia, 2010. |
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http://repositorio.bc.ufg.br/tede/handle/tde/1068 |
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ark:/38995/0013000009pxg |
identifier_str_mv |
OTTO, Carlos Rangel Neves. Preparation, characterization and evaluation of iron oxides and cobalt supported on activated carbon and polymeric catalysts for the dehydrogenation of ethylbenzene. 2010. 117 f. Dissertação (Mestrado em Educação em Química) - Universidade Federal de Goiás, Goiânia, 2010. ark:/38995/0013000009pxg |
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http://repositorio.bc.ufg.br/tede/handle/tde/1068 |
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UFG |
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Universidade Federal de Goiás |
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