Banca de QUALIFICAÇÃO: WESLEY EULÁLIO CABRAL CAVALCANTI

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : WESLEY EULÁLIO CABRAL CAVALCANTI
DATE: 12/12/2022
TIME: 14:00
LOCAL: Auditório do Química III
TITLE:

Conversion of glycerol in the presence of ethanol using catalysts based on CoFe2O4/SBA-15.

KEY WORDS:

Glycerol. SBA-15. Cobalt Ferrite. Conversion. Ethanol.

PAGES: 80
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Cinética Química e Catálise
SUMMARY:

Glycerol is a byproduct of biodiesel, therefore, the growth of production of this biofuel on a global scale has caused an increase in the supply of glycerol, increasing its market value significantly. To improve the economic efficiency and ecological standards of biodiesel production, they have sought to convert glycerol into products with greater added value. In this sense, this work focused on synthesizing and characterizing the cobalt ferrite-based solid supported on SBA-15 (CoFe2O4/SBA-15) to act as a catalyst in the glycerol conversion reaction in the presence of ethanol. The Support was synthesized via hydrothermal method using P123 as organic director and TEOS as silica source. While the synthesis of the catalyst occurred through the impregnation of precursors of Fe3+ and Co2+ via the Pechini method. Characterizations via X-ray diffraction (XRD) and FTIR spectroscopy confirmed the schemes of SBA-15 and CoFe2O4/SBA-15. A N2 physisorption analysis showed a surface area of 372 m2/g and a total pore volume of 0.65 cm3/g for the catalyst, indicating the presence of oxide on the surface and in the mesochannels of the support. Through scanning electron microscopy (SEM) it was confirmed that the support morphology was maintained after the impregnation process. Already from the transmission electron microscopy (TEM) an average particle size of 6.19 nm was measured for the supported cobalt ferrite. Raman spectroscopy allowed characterizing the ferrite present in the catalyst as a mixed spinel with an estimated degree of inversion (δ) of 0.4. The redox property of the catalyst was evaluated via the temperature reduction program (TPR-H2) which showed reduction events above 400°C referring to the reduction of Co2+ and Fe3+. The acid-base properties of the supported cobalt ferrite indicated the presence of basic basic sites via temperature programmed CO2  desorption (TPD-CO2) and the presence of suppressed Lewis sites via NO and Pyridine adsorption following FTIR analysis. The nature of the acid/base sites will be of fundamental importance for understanding the processes that occur during the glycerol conversion reaction.

COMMITTEE MEMBERS:
Interna - 349770 - DULCE MARIA DE ARAUJO MELO
Externo ao Programa - 1674707 - MARCO ANTONIO MORALES TORRES - nullPresidente - 2087667 - TIAGO PINHEIRO BRAGA