Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol
Autor(a) principal: | |
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Data de Publicação: | 1999 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da Universidade Estadual de Maringá (RI-UEM) |
Texto Completo: | http://repositorio.uem.br:8080/jspui/handle/1/3737 |
Resumo: | In this work it was tried to evaluate the influence of the preparation method of Cu/Nb2O5/Al2O3 catalysts on the generation of the copper-support interaction as well as the efficiency of that interaction in the ethanol steam reforming reaction. The catalysts were prepared by three methods: recipient wet impregnation, ion exchange and precipitation. For each method the supports Nb2O5, Nb2O5/Al2O3 and Al2O3 were used. The prepared samples were characterized by elementary analysis of atomic absorption, specific total superficial area (BET), diffuse reflectance spectroscopy (DRS), temperature programmed reduction (TPR) and metallic area of copper by N2O decomposition. The TPR analysis indicated the presence of the interaction in all the catalysts. They presented different reduction percentages and profiles, independent of the preparation method and support. By DRS, it was verified that the preparation method and the influence of the support generate differentiated phases, as well as their amounts. The absorption maxima around 360 nm in the catalysts that contain alumina evidence the presence of (Cu-O-Cu)n clusters. For the binary catalysts with Nb2O5 and ternary, the maximum band around 444 nm, shows strong Cu-Nb interaction and the bands above 800 nm suggest the presence of highly distorted NbO6 octahedra with Nb=O bonds responsible for the Lewis acid sites as well as slightly distorted NbO7 and NbO8 octahedra with Nb = O bonds responsible for the Brönsted acid sites. The analyses of metallic area evidenced SMSI effect in the Cu/Nb2O5 catalysts independent of the preparation method. The importance of the interaction as responsible for the generation of the active sites was checked by the catalytic test. The reaction used was the ethanol steam reforming and it was verified that independent of the preparation method or the alumina presence, the catalysts with smaller copper amount are more actives. The catalysts prepared by the ion exchange method are the ones that more convert the ethanol in relation to the different supports, mainly those that contain Nb2O5 showing the importance of the copper-niobia interaction in the conversion, because in those catalysts a larger dispersion of the copper on the surface of the support occurs, promoting larger exposition of the sites where the interaction and conversion take place. The largest selectivity and yield were found in the Cu/Nb2O5 catalysts prepared by wet impregnation. |
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Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanolEffects of preparation methods of cu/nb2o5/al2o3 catalysts: characterization and catalytic reactivity in the h2 production from ethanolCatalisadores metálicos de Cu - Métodos de preparaçãoEspectrofometriaCatalisadores - Métodos de preparaçãoEngenhariasEngenharia QuímicaIn this work it was tried to evaluate the influence of the preparation method of Cu/Nb2O5/Al2O3 catalysts on the generation of the copper-support interaction as well as the efficiency of that interaction in the ethanol steam reforming reaction. The catalysts were prepared by three methods: recipient wet impregnation, ion exchange and precipitation. For each method the supports Nb2O5, Nb2O5/Al2O3 and Al2O3 were used. The prepared samples were characterized by elementary analysis of atomic absorption, specific total superficial area (BET), diffuse reflectance spectroscopy (DRS), temperature programmed reduction (TPR) and metallic area of copper by N2O decomposition. The TPR analysis indicated the presence of the interaction in all the catalysts. They presented different reduction percentages and profiles, independent of the preparation method and support. By DRS, it was verified that the preparation method and the influence of the support generate differentiated phases, as well as their amounts. The absorption maxima around 360 nm in the catalysts that contain alumina evidence the presence of (Cu-O-Cu)n clusters. For the binary catalysts with Nb2O5 and ternary, the maximum band around 444 nm, shows strong Cu-Nb interaction and the bands above 800 nm suggest the presence of highly distorted NbO6 octahedra with Nb=O bonds responsible for the Lewis acid sites as well as slightly distorted NbO7 and NbO8 octahedra with Nb = O bonds responsible for the Brönsted acid sites. The analyses of metallic area evidenced SMSI effect in the Cu/Nb2O5 catalysts independent of the preparation method. The importance of the interaction as responsible for the generation of the active sites was checked by the catalytic test. The reaction used was the ethanol steam reforming and it was verified that independent of the preparation method or the alumina presence, the catalysts with smaller copper amount are more actives. The catalysts prepared by the ion exchange method are the ones that more convert the ethanol in relation to the different supports, mainly those that contain Nb2O5 showing the importance of the copper-niobia interaction in the conversion, because in those catalysts a larger dispersion of the copper on the surface of the support occurs, promoting larger exposition of the sites where the interaction and conversion take place. The largest selectivity and yield were found in the Cu/Nb2O5 catalysts prepared by wet impregnation.Neste trabalho procurou-se avaliar a influência do método de preparação de catalisadores Cu/Nb205/Al203 na geração da interação cobre-suporte, bem como a eficiência dessa interação na reação de reforma a vapor do etanol. Os catalisadores foram preparados por três métodos: impregnação úmida, troca iônica e precipitação. Para cada método foram utilizados os suportes Nb205, Nb205/Al2O3 e Al2O3. As amostras preparadas foram caracterizadas por análise elementar de absorção atômica, área superficial total específica (BET), espectroscopia de reflectância difusa (DRS), redução à temperatura programada (TPR) e área metálica de cobre por decomposição de N20. As análises de TPR indicaram a presença da interação em todos os catalisadores. Apresentou diferentes porcentagens de redução e perfis, independente do método de preparação e do suporte utilizado. Por DRS, verificou-se que o método de preparação e a influência do suporte geram fases diferenciadas, bem como suas quantidades. Os máximos de absorção em torno de 360 nm nos catalisadores que contêm alumina evidenciam a presença de grupos (Cu - O - Cu)n. Para os catalisadores binários com Nb205 e ternários, a banda máxima em tomo de 444 nm, mostra forte interação Cu-Nb e as bandas acima de 800 nm sugerem a presença de espécies octaédricas altamente distorcidas Nb06 com ligações Nb=O responsáveis pelos sítios ácidos de Lewis bem como Nb07 e Nb08 com ligações Nb - O levemente distorcidas responsáveis pelos sítios ácidos de Brönsted. As análises de área metálica evidenciaram o efeito SMSI nos catalisadores Cu/Nb205 independente do método de preparação. A importância da interação como responsável pela geração do sítio ativo foi comprovada pelo teste catalítico realizado. Foi utilizada a reação de reforma a vapor do etanol e verificou-se que, independente do método de preparação ou da presença de alumina, os catalisadores com menor teor de cobre são mais ativos. Os catalisadores preparados pelo método de troca iônica são os que mais convertem o etanol em relação aos diferentes suportes, principalmente aqueles que contém Nb205 mostrando a importância da interação cobre-nióbio na conversão, pois nesses catalisadores ocorre maior dispersão do cobre sobre a superfície do suporte promovendo maior exposição dos sítios onde ocorre a interação e a conversão. Maior seletividade e rendimento foram encontrados nos catalisadores Cu/Nb205 preparados por impregnação.98 fUniversidade Estadual de MaringáBrasilPrograma de Pós-Graduação em Engenharia QuímicaUEMMaringá, PRCentro de TecnologiaNádia Regina Camargo Fernandes-MachadoVeronice Slusarki Santana [Co-orientador] - UEMMaria Angélica Simões Dornellas de Barros - UEMAndréia Cristina FurtadoMarochio, Ivan Jefferson2018-04-17T17:42:55Z2018-04-17T17:42:55Z1999info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesishttp://repositorio.uem.br:8080/jspui/handle/1/3737porinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)instname:Universidade Estadual de Maringá (UEM)instacron:UEM2024-01-24T18:31:36Zoai:localhost:1/3737Repositório InstitucionalPUBhttp://repositorio.uem.br:8080/oai/requestopendoar:2024-04-23T14:56:53.439594Repositório Institucional da Universidade Estadual de Maringá (RI-UEM) - Universidade Estadual de Maringá (UEM)false |
dc.title.none.fl_str_mv |
Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol Effects of preparation methods of cu/nb2o5/al2o3 catalysts: characterization and catalytic reactivity in the h2 production from ethanol |
title |
Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol |
spellingShingle |
Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol Marochio, Ivan Jefferson Catalisadores metálicos de Cu - Métodos de preparação Espectrofometria Catalisadores - Métodos de preparação Engenharias Engenharia Química |
title_short |
Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol |
title_full |
Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol |
title_fullStr |
Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol |
title_full_unstemmed |
Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol |
title_sort |
Efeitos dos métodos de preparação de catalisadores Cu/Nb2O5/Al2O3: caracterização e reatividade catalítica na produção de H2 a partir de etanol |
author |
Marochio, Ivan Jefferson |
author_facet |
Marochio, Ivan Jefferson |
author_role |
author |
dc.contributor.none.fl_str_mv |
Nádia Regina Camargo Fernandes-Machado Veronice Slusarki Santana [Co-orientador] - UEM Maria Angélica Simões Dornellas de Barros - UEM Andréia Cristina Furtado |
dc.contributor.author.fl_str_mv |
Marochio, Ivan Jefferson |
dc.subject.por.fl_str_mv |
Catalisadores metálicos de Cu - Métodos de preparação Espectrofometria Catalisadores - Métodos de preparação Engenharias Engenharia Química |
topic |
Catalisadores metálicos de Cu - Métodos de preparação Espectrofometria Catalisadores - Métodos de preparação Engenharias Engenharia Química |
description |
In this work it was tried to evaluate the influence of the preparation method of Cu/Nb2O5/Al2O3 catalysts on the generation of the copper-support interaction as well as the efficiency of that interaction in the ethanol steam reforming reaction. The catalysts were prepared by three methods: recipient wet impregnation, ion exchange and precipitation. For each method the supports Nb2O5, Nb2O5/Al2O3 and Al2O3 were used. The prepared samples were characterized by elementary analysis of atomic absorption, specific total superficial area (BET), diffuse reflectance spectroscopy (DRS), temperature programmed reduction (TPR) and metallic area of copper by N2O decomposition. The TPR analysis indicated the presence of the interaction in all the catalysts. They presented different reduction percentages and profiles, independent of the preparation method and support. By DRS, it was verified that the preparation method and the influence of the support generate differentiated phases, as well as their amounts. The absorption maxima around 360 nm in the catalysts that contain alumina evidence the presence of (Cu-O-Cu)n clusters. For the binary catalysts with Nb2O5 and ternary, the maximum band around 444 nm, shows strong Cu-Nb interaction and the bands above 800 nm suggest the presence of highly distorted NbO6 octahedra with Nb=O bonds responsible for the Lewis acid sites as well as slightly distorted NbO7 and NbO8 octahedra with Nb = O bonds responsible for the Brönsted acid sites. The analyses of metallic area evidenced SMSI effect in the Cu/Nb2O5 catalysts independent of the preparation method. The importance of the interaction as responsible for the generation of the active sites was checked by the catalytic test. The reaction used was the ethanol steam reforming and it was verified that independent of the preparation method or the alumina presence, the catalysts with smaller copper amount are more actives. The catalysts prepared by the ion exchange method are the ones that more convert the ethanol in relation to the different supports, mainly those that contain Nb2O5 showing the importance of the copper-niobia interaction in the conversion, because in those catalysts a larger dispersion of the copper on the surface of the support occurs, promoting larger exposition of the sites where the interaction and conversion take place. The largest selectivity and yield were found in the Cu/Nb2O5 catalysts prepared by wet impregnation. |
publishDate |
1999 |
dc.date.none.fl_str_mv |
1999 2018-04-17T17:42:55Z 2018-04-17T17:42:55Z |
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.uri.fl_str_mv |
http://repositorio.uem.br:8080/jspui/handle/1/3737 |
url |
http://repositorio.uem.br:8080/jspui/handle/1/3737 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade Estadual de Maringá Brasil Programa de Pós-Graduação em Engenharia Química UEM Maringá, PR Centro de Tecnologia |
publisher.none.fl_str_mv |
Universidade Estadual de Maringá Brasil Programa de Pós-Graduação em Engenharia Química UEM Maringá, PR Centro de Tecnologia |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da Universidade Estadual de Maringá (RI-UEM) instname:Universidade Estadual de Maringá (UEM) instacron:UEM |
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Universidade Estadual de Maringá (UEM) |
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UEM |
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UEM |
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Repositório Institucional da Universidade Estadual de Maringá (RI-UEM) |
collection |
Repositório Institucional da Universidade Estadual de Maringá (RI-UEM) |
repository.name.fl_str_mv |
Repositório Institucional da Universidade Estadual de Maringá (RI-UEM) - Universidade Estadual de Maringá (UEM) |
repository.mail.fl_str_mv |
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