Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador
Autor(a) principal: | |
---|---|
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/8770 |
Resumo: | The CO preferential oxidation reaction (PROX) is used in the purification of hydrogen streams for various applications. Since the discovery of improved catalytic properties of gold particles, at nanometer range, in the CO oxidation reaction at low temperature, Au catalysts have been the subject of numerous investigations of CO oxidation and PROX. Concerning the heterogeneous catalysis, the catalyst activity is determined by several factors: the nanoparticles size, the metal loading and dispersion, the nature and porosity of the support, and the metal/support interaction. To understand the dependence of the support and the influence of the synthesizing method on the material properties and catalytic performances, gold nanoparticles supported on three different oxides (CeO2, MnO2 and TiO2) were successfully synthesized by the deposition precipitation (DP) method, using urea, and modified polyol (MP) method, using PVP as surfactant and sodium borohydride as reducing agent. Additionally, Au/SiO2 was obtained by the DP method. Characterizations were performed to assess the crystallinity, the metal mass percentage, the reduction temperatures and the respective reducing gas consumptions of pure oxides and supported materials synthesized by both methods. In addition, microscopic pictures were obtained to evaluate the materials morphology and the gold nanoparticles diameter. The Au catalysts synthesized by the DP method presented smaller particle sizes as compared to catalysts obtained by the MP method. Catalytic evaluation of the CO oxidation and PROX reactions were performed using temperature ramp starting at room temperature up to 200 °C. As a comparative parameter, the ratio between the catalyst mass and the gas feed flow remained constant at 1 mg / 1 mL / min for all reactions. The results showed that Au supported on TiO2 prepared by the DP method presented complete CO conversion at room temperature, but with the simultaneous supply of H2, this catalyst tends to oxidize H2, decreasing the CO conversion activity. On the other hand, the Au/CeO2 catalyst prepared by the DP method presented activity up to about 200 °C for PROX and better selectivity towards the CO2 formation. |
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Miranda, Aline Rodrigues LopesAssaf, José Mansurhttp://lattes.cnpq.br/9563312407691130Gomes, Janaina Fernandeshttp://lattes.cnpq.br/6718634914051168http://lattes.cnpq.br/2338318076586637c501ee99-14ec-4330-8014-04ea84e4e0de2017-05-23T19:58:53Z2017-05-23T19:58:53Z2016-03-29MIRANDA, Aline Rodrigues Lopes. Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador. 2016. Dissertação (Mestrado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8770.https://repositorio.ufscar.br/handle/ufscar/8770The CO preferential oxidation reaction (PROX) is used in the purification of hydrogen streams for various applications. Since the discovery of improved catalytic properties of gold particles, at nanometer range, in the CO oxidation reaction at low temperature, Au catalysts have been the subject of numerous investigations of CO oxidation and PROX. Concerning the heterogeneous catalysis, the catalyst activity is determined by several factors: the nanoparticles size, the metal loading and dispersion, the nature and porosity of the support, and the metal/support interaction. To understand the dependence of the support and the influence of the synthesizing method on the material properties and catalytic performances, gold nanoparticles supported on three different oxides (CeO2, MnO2 and TiO2) were successfully synthesized by the deposition precipitation (DP) method, using urea, and modified polyol (MP) method, using PVP as surfactant and sodium borohydride as reducing agent. Additionally, Au/SiO2 was obtained by the DP method. Characterizations were performed to assess the crystallinity, the metal mass percentage, the reduction temperatures and the respective reducing gas consumptions of pure oxides and supported materials synthesized by both methods. In addition, microscopic pictures were obtained to evaluate the materials morphology and the gold nanoparticles diameter. The Au catalysts synthesized by the DP method presented smaller particle sizes as compared to catalysts obtained by the MP method. Catalytic evaluation of the CO oxidation and PROX reactions were performed using temperature ramp starting at room temperature up to 200 °C. As a comparative parameter, the ratio between the catalyst mass and the gas feed flow remained constant at 1 mg / 1 mL / min for all reactions. The results showed that Au supported on TiO2 prepared by the DP method presented complete CO conversion at room temperature, but with the simultaneous supply of H2, this catalyst tends to oxidize H2, decreasing the CO conversion activity. On the other hand, the Au/CeO2 catalyst prepared by the DP method presented activity up to about 200 °C for PROX and better selectivity towards the CO2 formation.A reação de oxidação preferencial de CO (PROX) é utilizada na purificação de correntes de hidrogênio para diversas aplicações. Desde a descoberta da melhoria das propriedades catalíticas de partículas de ouro, em escala nanométrica, na reação de oxidação de CO a baixa temperatura, catalisadores de Au têm sido objeto de numerosas investigações em oxidação de CO e de PROX. No que diz respeito a catálise heterogênea, a atividade do catalisador é determinada por vários fatores: o tamanho das nanopartículas, a carga e dispersão metálica, a natureza e a porosidade do suporte, e a interação metal/suporte. Para entender a dependência do suporte e a influência do método de síntese nas propriedades dos materiais e nos desempenhos catalíticos, foram sintetizados com sucesso nanopartículas de ouro suportadas em 3 diferentes óxidos (CeO2, MnO2 e TiO2) pelos métodos de deposição precipitação (DP) com ureia e poliol modificado (PM) utilizando PVP como agente surfactante e borohidreto de sódio como agente redutor. Adionalmente, Au/SiO2 foi obtido pelo método DP. Foram realizadas caracterizações para avaliar a cristalinidade, porcentual mássico de metal, temperaturas de redução e respectivos consumos de gás redutor dos óxidos puros e dos materiais suportados sintetizados por ambos os métodos. Além disso, foram obtidas imagens de microscopia para avaliar a morfologia dos materiais e o diâmetro das nanopartículas de ouro. Os catalisadores de Au sintetizados pelo método DP apresentaram menores tamanhos de partícula, comparados aos catalisadores obtidos pelo método PM. A avaliação catalítica nas reações de oxidação de CO e PROX foram realizadas através de rampa de temperatura, começando pela temperatura ambiente e aquecendo até cerca de 200 ºC. Como parâmetro comparativo, a razão entre a massa de catalisador e a vazão dos gases alimentados manteve-se constante em 1 mg / 1 mL/min em todas as reações. Os resultados mostraram que o catalisador de Au suportado em TiO2 obtido pelo método DP apresentou conversão total de CO em temperatura ambiente, porém com a alimentação simultânea de H2, esse catalisador tende a oxidar o H2, diminuindo a atividade à conversão de CO. Por outro lado, o catalisador de Au/CeO2 preparado pelo método DP apresentou atividade até cerca de 200 ºC na PROX e melhor seletividade à formação de CO2.OutraPRH-ANP/MCT N° 44porUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Engenharia Química - PPGEQUFSCarNanopartículas de ouroInfluência de suportesCatáliseOxidação de COGold nanoparticlesSupports influenceCatalysisCO oxidation.ENGENHARIAS::ENGENHARIA QUIMICAOxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisadorinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisOnline600600d348d7f1-5523-40f0-9d08-b82dac73a6d8info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALDissARLM.pdfDissARLM.pdfapplication/pdf2999284https://repositorio.ufscar.br/bitstream/ufscar/8770/1/DissARLM.pdfcb32a2cd7ed71b40fd67f2b5604ce434MD51LICENSElicense.txtlicense.txttext/plain; charset=utf-81957https://repositorio.ufscar.br/bitstream/ufscar/8770/2/license.txtae0398b6f8b235e40ad82cba6c50031dMD52TEXTDissARLM.pdf.txtDissARLM.pdf.txtExtracted texttext/plain129426https://repositorio.ufscar.br/bitstream/ufscar/8770/3/DissARLM.pdf.txt5c5a49977dec7894d29d9872f577dfc7MD53THUMBNAILDissARLM.pdf.jpgDissARLM.pdf.jpgIM Thumbnailimage/jpeg6401https://repositorio.ufscar.br/bitstream/ufscar/8770/4/DissARLM.pdf.jpgb349331fddf3ef4e75864bb6de78c468MD54ufscar/87702023-09-18 18:31:24.1oai: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 |
Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador |
title |
Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador |
spellingShingle |
Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador Miranda, Aline Rodrigues Lopes Nanopartículas de ouro Influência de suportes Catálise Oxidação de CO Gold nanoparticles Supports influence Catalysis CO oxidation. ENGENHARIAS::ENGENHARIA QUIMICA |
title_short |
Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador |
title_full |
Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador |
title_fullStr |
Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador |
title_full_unstemmed |
Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador |
title_sort |
Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador |
author |
Miranda, Aline Rodrigues Lopes |
author_facet |
Miranda, Aline Rodrigues Lopes |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/2338318076586637 |
dc.contributor.author.fl_str_mv |
Miranda, Aline Rodrigues Lopes |
dc.contributor.advisor1.fl_str_mv |
Assaf, José Mansur |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/9563312407691130 |
dc.contributor.advisor-co1.fl_str_mv |
Gomes, Janaina Fernandes |
dc.contributor.advisor-co1Lattes.fl_str_mv |
http://lattes.cnpq.br/6718634914051168 |
dc.contributor.authorID.fl_str_mv |
c501ee99-14ec-4330-8014-04ea84e4e0de |
contributor_str_mv |
Assaf, José Mansur Gomes, Janaina Fernandes |
dc.subject.por.fl_str_mv |
Nanopartículas de ouro Influência de suportes Catálise Oxidação de CO |
topic |
Nanopartículas de ouro Influência de suportes Catálise Oxidação de CO Gold nanoparticles Supports influence Catalysis CO oxidation. ENGENHARIAS::ENGENHARIA QUIMICA |
dc.subject.eng.fl_str_mv |
Gold nanoparticles Supports influence Catalysis CO oxidation. |
dc.subject.cnpq.fl_str_mv |
ENGENHARIAS::ENGENHARIA QUIMICA |
description |
The CO preferential oxidation reaction (PROX) is used in the purification of hydrogen streams for various applications. Since the discovery of improved catalytic properties of gold particles, at nanometer range, in the CO oxidation reaction at low temperature, Au catalysts have been the subject of numerous investigations of CO oxidation and PROX. Concerning the heterogeneous catalysis, the catalyst activity is determined by several factors: the nanoparticles size, the metal loading and dispersion, the nature and porosity of the support, and the metal/support interaction. To understand the dependence of the support and the influence of the synthesizing method on the material properties and catalytic performances, gold nanoparticles supported on three different oxides (CeO2, MnO2 and TiO2) were successfully synthesized by the deposition precipitation (DP) method, using urea, and modified polyol (MP) method, using PVP as surfactant and sodium borohydride as reducing agent. Additionally, Au/SiO2 was obtained by the DP method. Characterizations were performed to assess the crystallinity, the metal mass percentage, the reduction temperatures and the respective reducing gas consumptions of pure oxides and supported materials synthesized by both methods. In addition, microscopic pictures were obtained to evaluate the materials morphology and the gold nanoparticles diameter. The Au catalysts synthesized by the DP method presented smaller particle sizes as compared to catalysts obtained by the MP method. Catalytic evaluation of the CO oxidation and PROX reactions were performed using temperature ramp starting at room temperature up to 200 °C. As a comparative parameter, the ratio between the catalyst mass and the gas feed flow remained constant at 1 mg / 1 mL / min for all reactions. The results showed that Au supported on TiO2 prepared by the DP method presented complete CO conversion at room temperature, but with the simultaneous supply of H2, this catalyst tends to oxidize H2, decreasing the CO conversion activity. On the other hand, the Au/CeO2 catalyst prepared by the DP method presented activity up to about 200 °C for PROX and better selectivity towards the CO2 formation. |
publishDate |
2016 |
dc.date.issued.fl_str_mv |
2016-03-29 |
dc.date.accessioned.fl_str_mv |
2017-05-23T19:58:53Z |
dc.date.available.fl_str_mv |
2017-05-23T19:58:53Z |
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 |
MIRANDA, Aline Rodrigues Lopes. Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador. 2016. Dissertação (Mestrado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8770. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/8770 |
identifier_str_mv |
MIRANDA, Aline Rodrigues Lopes. Oxidação preferencial de CO em catalisadores à base de ouro : estudo do efeito do suporte e do método de síntese do catalisador. 2016. Dissertação (Mestrado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8770. |
url |
https://repositorio.ufscar.br/handle/ufscar/8770 |
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por |
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600 600 |
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info:eu-repo/semantics/openAccess |
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openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.publisher.program.fl_str_mv |
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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UFSCAR |
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Repositório Institucional da UFSCAR |
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