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Abstract(s)
Neste projeto, pretendeu-se desenvolver novas macromoléculas (foto)ativas tendo
por base compostos porfirínicos e metaloporfirínicos bem como avaliar a sua
performance na promoção de reações de oxidação por irradiação da luz (idealmente solar)
e por irradiação micro-ondas. Com estes novos (foto)catalisadores esperávamos
desenvolver processos químicos mais eficientes e limpos.
A oxidação de álcoois e de hidrocarbonetos aromáticos sem adição de solvente
com espécies doadoras de oxigénio como o oxigénio singleto e os peróxidos são um
exemplo de um processo limpo e verde. Neste trabalho, foi estudada a oxidação de álcool
benzílico, 1-feniletanol e tolueno na presença e na ausência de um agente oxidante (tertbutilhidroperóxido,
70% aq.), utilizando como (foto)catalisadores as metaloporfirinas e
Por-PCs contendo metais de transição Cu(II) e Zn(II). Foi também avaliada a influência
de diferentes parâmetros, tais como a temperatura, o tempo de reação, a quantidade de
catalisador e a adição de aditivos.
Nas reações de foto-oxidação dos álcoois com as porfirinas base livre e as
metaloporfirinas de Zn(II), obtiveram-se baixas taxas de conversão, ca. 2.5%, utilizando
uma lâmpada LED 5.5 W, oxigénio atmosférico e sem adição de solventes.
Nas reações de oxidação por irradiação micro-ondas sem adição de solvente do 1-
feniletanol e do tolueno com um agente oxidante (TBHP), obtiveram-se rendimentos
máximos de 96% para o 1-feniletanol com o catalisador [Cu2(AcO)4(CuTPyP)1/2] e um
rendimento total máximo de 14% para o tolueno com o catalisador CuTPyP.
In this project, we intended to develop new (photo)active macromolecules based on porphyrin and metalloporphyrin compounds and to evaluate their performance in the promotion of oxidation reactions by light irradiation (ideally solar) and by microwave irradiation. With these new (photo)catalyst we pretended to develop more efficient and cleaner chemical processes. Solvent free oxidation of alcohols and aromatic hydrocarbons with oxygen donors such as single oxygen and peroxides, are an example of a cleaner and greener process. In this work, the oxidation of benzyl alcohol, 1-phenylethanol and toluene with or without the oxidizing agent (tert-butylhydroperoxide, 70% aq.) was studied using metalloporphyrins and Por-PCs containing Cu(II) and Zn(II) as (photo)catalysts. In order to optimize the results, the influence of different parameters, such as temperature, reaction time, amount of catalyst and additives were investigated. In the (photo)oxidation reactions of the alcohols with base porphyrins and Zn (II) metalloporphyrins, a conversion rate of about 2.5% was obtained using LED lamp 5.5 W and atmospheric oxygen without addition of solvents. In the solvent free microwave assisted peroxidative oxidation of 1-phenylethanol and toluene, were obtained the maximum yields of 96% for the 1-phenylethanol with the [Cu2(AcO)4(CuTPyP)1/2] catalyst and a maximum total yield of 14% for the toluene with the CuTPyP catalyst.
In this project, we intended to develop new (photo)active macromolecules based on porphyrin and metalloporphyrin compounds and to evaluate their performance in the promotion of oxidation reactions by light irradiation (ideally solar) and by microwave irradiation. With these new (photo)catalyst we pretended to develop more efficient and cleaner chemical processes. Solvent free oxidation of alcohols and aromatic hydrocarbons with oxygen donors such as single oxygen and peroxides, are an example of a cleaner and greener process. In this work, the oxidation of benzyl alcohol, 1-phenylethanol and toluene with or without the oxidizing agent (tert-butylhydroperoxide, 70% aq.) was studied using metalloporphyrins and Por-PCs containing Cu(II) and Zn(II) as (photo)catalysts. In order to optimize the results, the influence of different parameters, such as temperature, reaction time, amount of catalyst and additives were investigated. In the (photo)oxidation reactions of the alcohols with base porphyrins and Zn (II) metalloporphyrins, a conversion rate of about 2.5% was obtained using LED lamp 5.5 W and atmospheric oxygen without addition of solvents. In the solvent free microwave assisted peroxidative oxidation of 1-phenylethanol and toluene, were obtained the maximum yields of 96% for the 1-phenylethanol with the [Cu2(AcO)4(CuTPyP)1/2] catalyst and a maximum total yield of 14% for the toluene with the CuTPyP catalyst.
Description
Trabalho final de mestrado para obtenção do grau de mestre em Engenharia Química e Biológica
Keywords
Porfirinas Porphyrins Metaloporfirinas Metalloporphyrins (foto)catálise (photo)catalysis Micro-ondas Microwave assisted Álcoois Alcohols Hidrocarbonetos aromáticos Aromatic hydrocarbons Por-PCs
Citation
FONTE, Daniela Alexandra Gonçalves da - Desenvolvimento e avaliação de novos (foto)catalisadores. Lisboa: Instituto Superior de Engenharia de Lisboa, 2017. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa