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Advisor(s)
Abstract(s)
O objetivo do presente trabalho foi testar a atividade catalítica de materiais híbridos de ferro suportado em zeólitos hierárquicos na reação de oxidação de 1-feniletanol a acetofenona. Os zeólitos utilizados no trabalho foram o beta (BEA), com uma razão de Si/Al de 12,5, a mordenite (MOR) com uma razão de Si/Al 14,6 e o ZSM-5 (MFI) com uma razão de Si/Al 15. Para introduzir mesoporosidade e criar suportes hierárquicos, os zeólitos sofreram tratamento alcalino e ácido. O tratamento alcalino consiste no aquecimento do zeólito em solução alcalina com concentrações de NaOH variáveis dependentes da estrutura zeolítica. O tratamento ácido consiste no aquecimento do zeólito em solução ácida com HCl. Os materiais foram caracterizados por difração de raios-X, microscopia eletrónica de transmissão (TEM) e por adsorção de azoto a -196 °C e a quantidade de Fe foi medida pela técnica de ICP.
A imobilização do metal foi feita por mistura mecânica com a utilização do moinho de bolas com sais de Fe, como FeCl2·4H2O e FeCl3·6H2O. De seguida, o desempenho catalítico dos materiais preparados é avaliado na reação da oxidação de 1-feniletanol. A análise dos resultados dos ensaios catalíticos demonstra que o zeólito FeII@B02AT é o mais promissor com rendimentos de 46 % e seletividade de 100 %.
The aim of this study was to test the catalytic activity of iron hybrid materials supported on hierarchical zeolites in the oxidation reaction of 1-phenylethanol to acetophenone. The zeolites used in the work were beta (BEA), with a Si/Al ratio of 12.5, mordenite (MOR) with a Si/Al ratio of 14.6 and ZSM-5 with a Si/Al ratio of 15. To produce mesoporosity and create hierarchical supports, zeolites were treated with alkaline and acid treatment. The alkaline treatment procedure consists of heating the zeolite in alkaline solution with the concentration of NaOH dependent on the zeolitic structure in question. The acid treatment consists on the heating of the zeolite in an acidic solution with HCl. The materials were characterized by X-ray diffraction, transmission electron microscopy (TEM) and nitrogen adsorption at -196 ° C and the amount of Fe was measured by the ICP technique. The immobilization of the metal was made by mechanical mixing with the use of ball milling and Fe salts, such as FeCl2·4H2O and FeCl3·6H2O. The catalytic performance of the prepared materials is evaluated in the oxidation reaction of 1-phenylethanol. The analysis of the results of the catalytic assays shows that FeII @ B02AT zeolite is the most promising with 46% yields and 100% selectivity.
The aim of this study was to test the catalytic activity of iron hybrid materials supported on hierarchical zeolites in the oxidation reaction of 1-phenylethanol to acetophenone. The zeolites used in the work were beta (BEA), with a Si/Al ratio of 12.5, mordenite (MOR) with a Si/Al ratio of 14.6 and ZSM-5 with a Si/Al ratio of 15. To produce mesoporosity and create hierarchical supports, zeolites were treated with alkaline and acid treatment. The alkaline treatment procedure consists of heating the zeolite in alkaline solution with the concentration of NaOH dependent on the zeolitic structure in question. The acid treatment consists on the heating of the zeolite in an acidic solution with HCl. The materials were characterized by X-ray diffraction, transmission electron microscopy (TEM) and nitrogen adsorption at -196 ° C and the amount of Fe was measured by the ICP technique. The immobilization of the metal was made by mechanical mixing with the use of ball milling and Fe salts, such as FeCl2·4H2O and FeCl3·6H2O. The catalytic performance of the prepared materials is evaluated in the oxidation reaction of 1-phenylethanol. The analysis of the results of the catalytic assays shows that FeII @ B02AT zeolite is the most promising with 46% yields and 100% selectivity.
Description
Trabalho final de mestrado para obtenção do grau de mestre em Engenharia Química e Biológica
Keywords
Zeólitos hierárquicos Hierarchical zeolites Dessilicação Desilification Tratamento ácido Acid treatment Oxidação Oxidation Catálise heterogénea Heterogeneous catalysis Álcool secundário Secondary alcohol Mesoporosidade Mesoporosity 1-feniletanol 1-phenylethanol Acetofenona Acetophenone MOR MFI BEA
Citation
ANSARI, Leonardo Morgado de Sousa - Aplicação de zeólitos hierárquicos a reações de oxidação catalítica sob ação de radiação micro-ondas. Lisboa: Instituto Superior de Engenharia de Lisboa, 2019. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa