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Abstract(s)
Os nanopontos de carbono (NPCs) podem ser produzidos através de diversas fontes de carbono, incluindo resíduos industriais, e conceptualmente desenvolvidos para a melhoria de processos catalíticos na oxidação de álcoois, quer por fotocatálise quer por oxidação química.
O presente trabalho apresenta a síntese de NPCs derivados das águas residuais da indústria de produção de azeite, aplicando métodos simples e ambientalmente sustentáveis, e o seu uso como catalisadores em reações orgânicas de interesse industrial.
A primeira parte desta tese diz respeito à síntese e caracterização de NPCs e compósitos. Os materiais sintetizados foram analisados e caracterizados estruturalmente por espetroscopia de infravermelho com transformada de Fourier (FTIR). As propriedades fotofísicas destes materiais foram avaliadas por técnicas de absorção no estado fundamental e luminescência de estado estacionário. A caracterização eletroquímica dos NPCs foi estudada por voltametria cíclica (VC).
A segunda parte consiste na avaliação da capacidade, tanto dos NPCs como dos compósitos sintetizados, de serem utilizados como catalisadores em processos oxidativos de álcoois.
Para os estudos catalíticos selecionou-se o álcool benzílico como substrato modelo. Nos diversos procedimentos de oxidação química e fotoquímica, investigaram-se uma série de parâmetros, como o tempo de reação, quantidade de NPCs, tipo de oxidante e temperatura, com vista a otimização da conversão e seletividade do processo.
Carbon nanodots (CNDs) can be produced from various carbon sources, including industrial wastes, and conceptually designed to improve catalytic processes for the oxidation of alcohols, either by photocatalysis or by chemical oxidation. This work presents the synthesis of CNDs derived from olive mill wastewaters (OMWWs), using simple environmental-friendly procedures and its as catalysts in sustainable organic reactions of industrial interest. The first part of work concerns to the synthesis and characterization of CNDs and composites. The as-synthesized CNDs and composites derived thereof were analysed and structurally characterized by Fourier transform infrared spectroscopy (FTIR). The photophysical properties of these materials were evaluated by ground state absorption and steady state luminescence techniques. The electrochemical characterization of CNDs was studied by cyclic voltammetry (CV). The second part concerns to the evaluation of the ability, of both CNDs and composites synthetized, to behave as catalysts in oxidation processes of alcohols. Benzyl alcohol was selected for the catalytic studies. Following chemical and photochemical procedures, a series of reaction parameters, e.g. reaction time, temperature, amount of CNDs and oxidant type, were surveyed.
Carbon nanodots (CNDs) can be produced from various carbon sources, including industrial wastes, and conceptually designed to improve catalytic processes for the oxidation of alcohols, either by photocatalysis or by chemical oxidation. This work presents the synthesis of CNDs derived from olive mill wastewaters (OMWWs), using simple environmental-friendly procedures and its as catalysts in sustainable organic reactions of industrial interest. The first part of work concerns to the synthesis and characterization of CNDs and composites. The as-synthesized CNDs and composites derived thereof were analysed and structurally characterized by Fourier transform infrared spectroscopy (FTIR). The photophysical properties of these materials were evaluated by ground state absorption and steady state luminescence techniques. The electrochemical characterization of CNDs was studied by cyclic voltammetry (CV). The second part concerns to the evaluation of the ability, of both CNDs and composites synthetized, to behave as catalysts in oxidation processes of alcohols. Benzyl alcohol was selected for the catalytic studies. Following chemical and photochemical procedures, a series of reaction parameters, e.g. reaction time, temperature, amount of CNDs and oxidant type, were surveyed.
Description
Trabalho final de mestrado para a obtenção do grau de mestre em Engenharia Química e Biológica
Keywords
nanopontos de carbono (NPCs) arbon nanodots (CNDs) compósitos composites, catálise catalysis fotocatálise photocatalysis oxidação de álcoois oxidation of alcohols
Citation
CRUZ, Jéssica Cláudio - Nanomateriais de carbono como catalisadores de processos oxidativos industrialmente sustentáveis. Lisboa: Instituto Superior de Engenharia de Lisboa, 2018. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa