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Abstract(s)
Este trabalho exibe nanotubos de titanatos (TNTs), titanatos modificados com pontos de carbono (TNT_C_dots), nanopartículas de dióxido de titânio dopadas com cobalto (Ti1-xCoxO2) e nanocompósitos de CoFe2O4 e NiFe2O4 suportados em grafite/celulose como potenciais catalisadores com interesse industrial em reações orgânicas, mais especificamente oxidação química de álcool benzílico. Os nanomateriais TNTs e TNT_C_dots também foram testados nas reações de oxidação química que utilizam como substrato o 1-feniletanol. Foi efetuado o estudo catalítico onde foi analisado a variação de diversos parâmetros experimentais como a temperatura, quantidade de catalisador, tipo de oxidante, tempo de reação, aditivo, entre outros. Foram ainda realizados ensaios relativos a oxidação química utilizando método de aquecimento convencional e métodos alternativos como banho de ultrassons, sonda ultrassónica e micro-ondas. De modo a compreender a atividade e a sua alteração ao longo das reações químicas os catalisadores foram analisados e caracterizados anteriormente e posteriormente às reações catalíticas por espetroscopia de infravermelhos por transformada de Fourier (FTIR). Na reação de oxidação de álcool benzílico, as nanopartículas com maior dopagem de cobalto (10%) apresentam um valor superior de rendimento (29.2%) no ensaio a temperatura ambiente, mostrando-se como o catalisador mais eficiente para as nanopartículas testadas. No caso dos nanotubos de titanatos, o que demonstrou maior atividade catalítica foram os nanotubos de titanatos modificados com pontos de carbono (49.1%). Relativamente aos nanocompósitos, os que contêm o metal níquel, em especial os suportados em grafite, apresentam-se mais ativos (70.1%). Para a reação de oxidação do 1-feniletanol, os nanotubos de titanatos (TNT_160) apresentam um valor de rendimento de 98.9%, sendo considerados os com maior atividade nesta reação.
These work shows titanate nanotubes (TNTs), titanate modified with carbon dots (TNT_C_dots) and cobalt-doped titanium dioxide nanoparticles (Ti1-xCoxO2), nanocomposites (CoFe2O4 and NiFe2O4 supported in graphite/cellulose) as potential catalysts with industrial interest in organic reactions, specifically chemical oxidation of benzyl alcohol. TNTs and TNT_C_dots were also tested as catalysts in the oxidation using 1-phenylethanol as substrate. A catalytic study was performed by analyzing the variation of several experimental parameters such as temperature, amount of catalyst, type of oxidant, time of reaction, additive, among others. Chemical oxidation tests were performed using conventional heating, and alternative methods such as ultrasonic bath, ultrasonic probe and microwave. In order to understand the activity and alteration along the chemical reactions the compounds were analyzed and characterized before and after the catalytic reactions by Fourier Transform Infrared Spectroscopy (FTIR). In benzyl alcohol oxidation reaction, the nanoparticles doped with cobalt (10%) tested in room temperature have a higher yield value (29.2%). Titanate nanotubes modified with carbon dots (TNT_C_dots) showed a yield of 49.1%. For nanocomposites, those containing nickel, especially those supported in graphite, are more active (70.1%). For the 1-phenylethanol oxidation reaction, titanate nanotubes modified with carbon dots (TNT_C_dots) have a yield of 98.9%, considered the most active.
These work shows titanate nanotubes (TNTs), titanate modified with carbon dots (TNT_C_dots) and cobalt-doped titanium dioxide nanoparticles (Ti1-xCoxO2), nanocomposites (CoFe2O4 and NiFe2O4 supported in graphite/cellulose) as potential catalysts with industrial interest in organic reactions, specifically chemical oxidation of benzyl alcohol. TNTs and TNT_C_dots were also tested as catalysts in the oxidation using 1-phenylethanol as substrate. A catalytic study was performed by analyzing the variation of several experimental parameters such as temperature, amount of catalyst, type of oxidant, time of reaction, additive, among others. Chemical oxidation tests were performed using conventional heating, and alternative methods such as ultrasonic bath, ultrasonic probe and microwave. In order to understand the activity and alteration along the chemical reactions the compounds were analyzed and characterized before and after the catalytic reactions by Fourier Transform Infrared Spectroscopy (FTIR). In benzyl alcohol oxidation reaction, the nanoparticles doped with cobalt (10%) tested in room temperature have a higher yield value (29.2%). Titanate nanotubes modified with carbon dots (TNT_C_dots) showed a yield of 49.1%. For nanocomposites, those containing nickel, especially those supported in graphite, are more active (70.1%). For the 1-phenylethanol oxidation reaction, titanate nanotubes modified with carbon dots (TNT_C_dots) have a yield of 98.9%, considered the most active.
Description
Trabalho final de mestrado para obtenção do grau de mestre em Engenharia Química e Biológica
Keywords
Nanotubos de titanatos (TNTs) Titanate nanotubes (TNTs) Nanotubos de titanatos modificados com pontos de carbono (TNT_C_dots) Titanate nanotubes modified with carbon dots (TNT_C_dots) Nanopartículas de TiO2 dopadas com cobalto TiO2 nanoparticles doped with cobalt Nanocompósitos de ferrite Ferrite nanocomposites Oxidação do álcool benzílico Oxidation of benzyl alcohol Oxidação do 1-feniletanol Oxidation of 1-phenilethanol
Citation
ALVES, Sofia Santos Cunha - Oxidação catalítica de álcoois utilizando nanopartículas de TiO2 dopadas com cobalto e titanatos modificados com pontos de carbono. Lisboa: Instituto Superior de Engenharia de Lisboa, 2019. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa