Banca de DEFESA: PEDRO HENRIQUE DO NASCIMENTO SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : PEDRO HENRIQUE DO NASCIMENTO SILVA
DATE: 03/10/2025
TIME: 15:00
LOCAL: Auditório do NUPPRAR
TITLE:

Manganese-Catalyzed Hydrodecarboxylation of Oleaginous Biomass for the Production of Sustainable Aviation Fuels.

KEY WORDS:

redox-active ester; hydrodecarboxylation; manganese; sustainable hydrocarbons; babassu oil

PAGES: 90
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Síntese Orgânica
SUMMARY:

The diversification of the global energy matrix is essential to mitigate anthropogenic emissions and the negative impacts associated with greenhouse gases (GHG) from fossil fuel combustion, which in Brazil reached 428 Mt of CO₂ in 2023. In this context, the hydrodecarboxylation of fatty acids derivatized as N-hydroxyphthalimide (NHPI) redox-active esters emerges as a promising alternative for the production of renewable hydrocarbons applicable as fuels, standing out for not requiring severe temperature and pressure conditions, as well as eliminating the need for H₂(g) and the synthesis of catalysts with specific properties. This study focused on reductive metal catalysis mediated by manganese—a low-cost, non-toxic, and widely available metal. Reaction parameters such as solvent, catalyst, hydrogen source, additives, stoichiometry, concentration, time, temperature, and control reactions were evaluated. The hydrodecarboxylation of the redox-active ester derived from lauric acid afforded undecane with 70% yield and conversion above 99%, after an optimization process comprising 84 reactions under different conditions, including replicates. Subsequently, the reaction scope was expanded to other commercially available derivatized fatty acids, enabling the synthesis of sustainable hydrocarbons within the SAF range (C9–C17) with high selectivity, conversions above 87%, and yields between 41% and 70%. The one-pot methodology also proved promising, achieving conversions above 99% and yields between 27% and 56%, thereby reducing isolation, purification, and recrystallization steps of the starting material. An equimolar mixture of fatty acids was evaluated on a 1 mmol scale, resulting in conversion above 99% and an overall yield of 54%. The method was further applied to the hydrodecarboxylation of fatty acids derived from babassu oil, preceded by a scale-up of the reaction for the derivatization of fatty acids from the vegetable oil, reaching an overall yield of 60%. Thus, a complementary sustainable protocol was developed, operationally simple and able to overcome the limitations associated with conventional deoxygenation methods. Qualitative and quantitative characterization of the products was carried out by gas chromatography with flame ionization detector (GC-FID) and mass spectrometry (GC-MS).

COMMITTEE MEMBERS:
Presidente - 2140818 - AMANDA DUARTE GONDIM
Interno - 350509 - ANTONIO SOUZA DE ARAUJO
Externo à Instituição - JOAO PAULO DA COSTA EVANGELISTA - UFRN
Externa ao Programa - 2140775 - LIVIA NUNES CAVALCANTI - null