Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos
Autor(a) principal: | |
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Data de Publicação: | 2011 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFRN |
Texto Completo: | https://repositorio.ufrn.br/jspui/handle/123456789/15812 |
Resumo: | The main goal of this work was to produce nanosized ceramic materials of the family of the tungstates (tungstates of cerium and strontium), and test them for their catalytic activity in processes involving the transformation of methane (CH4). The methodology used for the synthesis of the ceramic powders involved the complexation combining EDTA-citrate. The materials characterization was performed using simple and differential thermogravimetry, x-ray diffraction, transmission electron microscopy, and energy dispersive spectroscopy (EDS). The microstructure analysis was performed using the refinement by the Rietveld method, and the crystallite size and distribution of the materials was elucidate by the Scherrer and Williamson-Hall methods. The conditions of the synthesis process for the three envisaged materials (SrWO4, SrWO4 using tungsten oxide concentrate as raw material, and Ce2(WO4)3) were adjusted to obtain a single phase crystalline material. The catalytic tests were carried out in the presence of methane and synthetic air, which is composed of 21% O2 and 79% N2. The analysis of the conversion of the reaction was done with the aid of an fourier transform infrared device (FTIR). The analysis showed that, structurally, the SrWO4 produced using raw materials of high and poor purity (99% and 92%, respectively) are similar. The ideal parameters of calcination, in the tested range, are temperature of 1000 °C and time of calcination 5 hours. For the Ce2(WO4)3, the ideal calcination time and are temperature 15 hours and 1000°C, respectively. The Williamson-Hall method provided two different distributions for the crystallite size of each material, whose values ranged between the nanometer and micrometer scales. According to method of Scherrer, all materials produced were composed of nanometric crystallites. The analyses of transmission electron microscopy confirmed the results obtained from the Williamson- Hall method for the crystallite size. The EDS showed an atomic composition for the metals in the SrWO4 that was different of the theoretical composition. With respect to the catalytic tests, all materials were found to be catalytically active, but the reaction process should be further studied and optimized. |
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Moriyama, André Luiz Lopeshttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781094H3Santos, Andarair Gomes doshttp://lattes.cnpq.br/3470634368296605Costa, Franciné Alves dahttp://lattes.cnpq.br/8698567925323942Souza, Carlson Pereira de2014-12-17T15:01:26Z2012-01-162014-12-17T15:01:26Z2011-07-21MORIYAMA, André Luiz Lopes. Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos. 2011. 83 f. Dissertação (Mestrado em Pesquisa e Desenvolvimento de Tecnologias Regionais) - Universidade Federal do Rio Grande do Norte, Natal, 2011.https://repositorio.ufrn.br/jspui/handle/123456789/15812The main goal of this work was to produce nanosized ceramic materials of the family of the tungstates (tungstates of cerium and strontium), and test them for their catalytic activity in processes involving the transformation of methane (CH4). The methodology used for the synthesis of the ceramic powders involved the complexation combining EDTA-citrate. The materials characterization was performed using simple and differential thermogravimetry, x-ray diffraction, transmission electron microscopy, and energy dispersive spectroscopy (EDS). The microstructure analysis was performed using the refinement by the Rietveld method, and the crystallite size and distribution of the materials was elucidate by the Scherrer and Williamson-Hall methods. The conditions of the synthesis process for the three envisaged materials (SrWO4, SrWO4 using tungsten oxide concentrate as raw material, and Ce2(WO4)3) were adjusted to obtain a single phase crystalline material. The catalytic tests were carried out in the presence of methane and synthetic air, which is composed of 21% O2 and 79% N2. The analysis of the conversion of the reaction was done with the aid of an fourier transform infrared device (FTIR). The analysis showed that, structurally, the SrWO4 produced using raw materials of high and poor purity (99% and 92%, respectively) are similar. The ideal parameters of calcination, in the tested range, are temperature of 1000 °C and time of calcination 5 hours. For the Ce2(WO4)3, the ideal calcination time and are temperature 15 hours and 1000°C, respectively. The Williamson-Hall method provided two different distributions for the crystallite size of each material, whose values ranged between the nanometer and micrometer scales. According to method of Scherrer, all materials produced were composed of nanometric crystallites. The analyses of transmission electron microscopy confirmed the results obtained from the Williamson- Hall method for the crystallite size. The EDS showed an atomic composition for the metals in the SrWO4 that was different of the theoretical composition. With respect to the catalytic tests, all materials were found to be catalytically active, but the reaction process should be further studied and optimized.O objetivo principal deste trabalho foi produzir materiais cerâmicos nanométricos da família dos tungstatos (tungstatos de cério e de estrôncio), e testá-los quanto às suas atividades catalíticas em processos envolvendo a transformação do gás metano (CH4). A metodologia empregada para a síntese dos pós cerâmicos envolveu o método de complexação combinando EDTA-Citrato. A caracterização dos materiais foi feita através das técnicas de termogravimetria simples e diferencial, difração de raios-x, microscopia eletrônica de transmissão, e espectroscopia de energia dispersiva (EDS). A análise da microestrutura foi realizada através do refinamento utilizando o método de Rietveld, e para a estimação do tamanho de grão e de sua distribuição foram utilizados os métodos de Scherrer e Williamson-Hall. As condições de obtenção dos três materiais desenvolvidos (SrWO4, SrWO4 utilizando concentrado de óxido de tungstênio como matéria-prima, e Ce2(WO4)3) foram ajustadas para a obtenção de um material cristalino monofásico. Os testes catalíticos exploratórios foram realizados na presença dos gases metano e ar sintético, composto por 21% de O2 e 79% N2. A análise da conversão foi feita com o auxílio de um equipamento de infravermelho à transformada de Fourier. As análises mostraram que, estruturalmente, os materiais SrWO4 produzidos com matériaprima de elevada pureza (99% de pureza) e oriunda do concentrado de óxido de tungstênio (92% de pureza) são semelhantes. Seus parâmetros ideais de produção, dentro do que foi testado, são temperatura de calcinação de 1000ºC e tempo de permanência de 5 horas na isoterma. Para o Ce2(WO4)3, as condições ideais dentro do que foi testado são temperatura de calcinação de 1000ºC e tempo de permanência na isoterma de 15 horas. O método de Williamson-Hall forneceu duas distribuições diferentes para o tamanho de cristalito de cada material, cujos valores oscilaram entre as escalas nanométricas e micrométricas. Com o método de Scherrer, todos os materiais produzidos possuíram tamanho de cristalito nanométrico. As análises de microscopia eletrônica de transmissão confirmaram o resultado obtido com o método de Williamson- Hall para o tamanho de cristalito. A EDS indicou a presença de divergências entre a composição atômica metálica teórica e experimental do SrWO4. Com relação aos testes catalíticos exploratórios, os materiais se mostraram ativos porém o processo reacional ainda precisa ser melhor estudado e otimizado.Conselho Nacional de Desenvolvimento Científico e Tecnológicoapplication/pdfporUniversidade Federal do Rio Grande do NortePrograma de Pós-Graduação em Engenharia QuímicaUFRNBRPesquisa e Desenvolvimento de Tecnologias RegionaisSíntese de nanomateriaisMétodo EDTA-CitratoCaracterização de pósTungstatosCatalisador.Synthesis of nanomaterialsCitrate-EDTA methodCharacterization of powdersTungstatesCatalyst.CNPQ::ENGENHARIAS::ENGENHARIA QUIMICASíntese e caracterização de tungstatos de cério e estrôncio para fins catalíticosinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNORIGINALAndreLLM_DISSERT.pdfapplication/pdf1863413https://repositorio.ufrn.br/bitstream/123456789/15812/1/AndreLLM_DISSERT.pdf1d92759b3bdf5371d233d97ad885e7afMD51TEXTAndreLLM_DISSERT.pdf.txtAndreLLM_DISSERT.pdf.txtExtracted texttext/plain124274https://repositorio.ufrn.br/bitstream/123456789/15812/6/AndreLLM_DISSERT.pdf.txtb7c7c208a2cffe7367a97eeb06a0d951MD56THUMBNAILAndreLLM_DISSERT.pdf.jpgAndreLLM_DISSERT.pdf.jpgIM Thumbnailimage/jpeg3406https://repositorio.ufrn.br/bitstream/123456789/15812/7/AndreLLM_DISSERT.pdf.jpg1d96bed65da26bd1344c586b91b59ed4MD57123456789/158122017-11-02 04:17:21.189oai:https://repositorio.ufrn.br:123456789/15812Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2017-11-02T07:17:21Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false |
dc.title.por.fl_str_mv |
Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos |
title |
Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos |
spellingShingle |
Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos Moriyama, André Luiz Lopes Síntese de nanomateriais Método EDTA-Citrato Caracterização de pós Tungstatos Catalisador. Synthesis of nanomaterials Citrate-EDTA method Characterization of powders Tungstates Catalyst. CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA |
title_short |
Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos |
title_full |
Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos |
title_fullStr |
Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos |
title_full_unstemmed |
Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos |
title_sort |
Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos |
author |
Moriyama, André Luiz Lopes |
author_facet |
Moriyama, André Luiz Lopes |
author_role |
author |
dc.contributor.authorID.por.fl_str_mv |
|
dc.contributor.advisorID.por.fl_str_mv |
|
dc.contributor.advisorLattes.por.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781094H3 |
dc.contributor.referees1.pt_BR.fl_str_mv |
Santos, Andarair Gomes dos |
dc.contributor.referees1ID.por.fl_str_mv |
|
dc.contributor.referees1Lattes.por.fl_str_mv |
http://lattes.cnpq.br/3470634368296605 |
dc.contributor.referees2.pt_BR.fl_str_mv |
Costa, Franciné Alves da |
dc.contributor.referees2ID.por.fl_str_mv |
|
dc.contributor.referees2Lattes.por.fl_str_mv |
http://lattes.cnpq.br/8698567925323942 |
dc.contributor.author.fl_str_mv |
Moriyama, André Luiz Lopes |
dc.contributor.advisor1.fl_str_mv |
Souza, Carlson Pereira de |
contributor_str_mv |
Souza, Carlson Pereira de |
dc.subject.por.fl_str_mv |
Síntese de nanomateriais Método EDTA-Citrato Caracterização de pós Tungstatos Catalisador. |
topic |
Síntese de nanomateriais Método EDTA-Citrato Caracterização de pós Tungstatos Catalisador. Synthesis of nanomaterials Citrate-EDTA method Characterization of powders Tungstates Catalyst. CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA |
dc.subject.eng.fl_str_mv |
Synthesis of nanomaterials Citrate-EDTA method Characterization of powders Tungstates Catalyst. |
dc.subject.cnpq.fl_str_mv |
CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA |
description |
The main goal of this work was to produce nanosized ceramic materials of the family of the tungstates (tungstates of cerium and strontium), and test them for their catalytic activity in processes involving the transformation of methane (CH4). The methodology used for the synthesis of the ceramic powders involved the complexation combining EDTA-citrate. The materials characterization was performed using simple and differential thermogravimetry, x-ray diffraction, transmission electron microscopy, and energy dispersive spectroscopy (EDS). The microstructure analysis was performed using the refinement by the Rietveld method, and the crystallite size and distribution of the materials was elucidate by the Scherrer and Williamson-Hall methods. The conditions of the synthesis process for the three envisaged materials (SrWO4, SrWO4 using tungsten oxide concentrate as raw material, and Ce2(WO4)3) were adjusted to obtain a single phase crystalline material. The catalytic tests were carried out in the presence of methane and synthetic air, which is composed of 21% O2 and 79% N2. The analysis of the conversion of the reaction was done with the aid of an fourier transform infrared device (FTIR). The analysis showed that, structurally, the SrWO4 produced using raw materials of high and poor purity (99% and 92%, respectively) are similar. The ideal parameters of calcination, in the tested range, are temperature of 1000 °C and time of calcination 5 hours. For the Ce2(WO4)3, the ideal calcination time and are temperature 15 hours and 1000°C, respectively. The Williamson-Hall method provided two different distributions for the crystallite size of each material, whose values ranged between the nanometer and micrometer scales. According to method of Scherrer, all materials produced were composed of nanometric crystallites. The analyses of transmission electron microscopy confirmed the results obtained from the Williamson- Hall method for the crystallite size. The EDS showed an atomic composition for the metals in the SrWO4 that was different of the theoretical composition. With respect to the catalytic tests, all materials were found to be catalytically active, but the reaction process should be further studied and optimized. |
publishDate |
2011 |
dc.date.issued.fl_str_mv |
2011-07-21 |
dc.date.available.fl_str_mv |
2012-01-16 2014-12-17T15:01:26Z |
dc.date.accessioned.fl_str_mv |
2014-12-17T15:01:26Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
MORIYAMA, André Luiz Lopes. Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos. 2011. 83 f. Dissertação (Mestrado em Pesquisa e Desenvolvimento de Tecnologias Regionais) - Universidade Federal do Rio Grande do Norte, Natal, 2011. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufrn.br/jspui/handle/123456789/15812 |
identifier_str_mv |
MORIYAMA, André Luiz Lopes. Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos. 2011. 83 f. Dissertação (Mestrado em Pesquisa e Desenvolvimento de Tecnologias Regionais) - Universidade Federal do Rio Grande do Norte, Natal, 2011. |
url |
https://repositorio.ufrn.br/jspui/handle/123456789/15812 |
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por |
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Universidade Federal do Rio Grande do Norte |
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Programa de Pós-Graduação em Engenharia Química |
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UFRN |
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BR |
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Pesquisa e Desenvolvimento de Tecnologias Regionais |
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Universidade Federal do Rio Grande do Norte |
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