Powered by OpenAIRE graph
Found an issue? Give us feedback
image/svg+xml art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos Open Access logo, converted into svg, designed by PLoS. This version with transparent background. http://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_white.svg art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos http://www.plos.org/ Repositório Científi...arrow_drop_down
image/svg+xml art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos Open Access logo, converted into svg, designed by PLoS. This version with transparent background. http://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_white.svg art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos http://www.plos.org/
versions View all 1 versions
addClaim

Desenvolvimento e avaliação de novos (foto)catalisadores

Authors: Fonte, Daniela Alexandra Gonçalves da;

Desenvolvimento e avaliação de novos (foto)catalisadores

Abstract

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.

Country
Portugal
Related Organizations
Keywords

Porphyrins, Metalloporphyrins, Alcohols, Microwave assisted, Por-PCs, Aromatic hydrocarbons, (foto)catálise, Micro-ondas, Porfirinas, Metaloporfirinas, Álcoois, (photo)catalysis, Hidrocarbonetos aromáticos

  • BIP!
    Impact byBIP!
    selected citations
    These citations are derived from selected sources.
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    0
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
    OpenAIRE UsageCounts
    Usage byUsageCounts
    visibility views 34
    download downloads 43
  • 34
    views
    43
    downloads
    Powered byOpenAIRE UsageCounts
Powered by OpenAIRE graph
Found an issue? Give us feedback
visibility
download
selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
views
OpenAIRE UsageCountsViews provided by UsageCounts
downloads
OpenAIRE UsageCountsDownloads provided by UsageCounts
0
Average
Average
Average
34
43
Green