Banca de QUALIFICAÇÃO: LETÍCIA FERREIRA LIMA MACHADO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LETÍCIA FERREIRA LIMA MACHADO
DATE: 20/12/2023
TIME: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/wagner-27
TITLE:

Synthesis, characterization and application of glycerol carbons with acidic and magnetic properties

PAGES: 30
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Cinética Química e Catálise
SUMMARY:

The increasing demand for fossil fuels has raised serious concerns, leading to a growing emphasis on exploring alternative renewable sources, particularly through the utilization of biomass. Hexoses, such as fructose and glucose, can be dehydrogenated to the high-value-added product 5-hydroxymethylfurfural (5-HMF). However, the conventional catalytic conversion processes for these hexoses involve the use of sulfuric acid (for fructose) and Lewis acids (for glucose), which makes the process difficult and harmful to the environment. To address these challenges, researchers have turned their attention to carbons with chemically modified surfaces, which have shown promise as solid catalysts. The task of simultaneously introducing both Lewis and Brønsted acidity into carbons has been a complex one. In response, new approaches were taken to prepare magnetic and acidic carbons. Coals with acidic and magnetic properties were prepared by the methods of hydrothermal carbonization and pyrolysis of glycerol, a co-product of biodiesel production, with sulfuric acid (H₂SO₄) and magnetite (Fe₃O₄), iron (III) chloride (FeCl₃) or nitrate of iron (III) (Fe(NO₃)9H₂O), as magnetic precursors. Through different characterization techniques, it was possible to elucidate physicochemical properties favorable to the catalytic process, including the incorporation of 1.63% of iron and 4.48 mmol g^-1 of sulfonic, carboxylic, phenolic and lactonic groups. These characteristics made it possible to convert 78.51% of the fructose and obtain a 71.35% yield of 5-HMF. In this way, it was possible to obtain a solid with high synthesis yield and with structural modifications capable of contributing to the catalysis of the fructose dehydrogenation reaction.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1601156 - WAGNER ALVES CARVALHO
Membro Titular - Examinador(a) Interno ao Programa - 1623562 - RODRIGO LUIZ OLIVEIRA RODRIGUES CUNHA
Membro Titular - Examinador(a) Externo à Instituição - JOSE GERALDO NERY - UNESP
Membro Suplente - Examinador(a) Interno ao Programa - 1762430 - DALMO MANDELLI
Membro Suplente - Examinador(a) Externo ao Programa - 163.918.148-21 - ANTÔNIO CARLOS FERREIRA BATISTA - IF UBERAB