Banca de DEFESA: CHRISTIAN MARCELO PARAGUASSU CECCHI

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : CHRISTIAN MARCELO PARAGUASSU CECCHI
DATA : 17/08/2018
HORA: 09:00
LOCAL: Sala 50 Pavilhão de Química
TÍTULO:

OXIDATION OF METHYL ESTERS OF FATTY ACIDS BY NIOBIUM OXIDE (V). A STUDY ON THE REACTIVITY OF THE CATALYST SURFACE

PALAVRAS-CHAVES:

Nb2O5; H2O2; methyl linoleate; Raman spectroscopy; oxidation; 9-oxo-nonanoic acid methyl ester; Hock rearrangement.

PÁGINAS: 130
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
RESUMO:

The catalytic properties of niobium oxide (V) (Nb2O5-CBMM) of different degrees: amorphous, optical and ultra-pure, untreated or heat treated at 400, 500, 700 and 900 ° C were studied, before and after the interaction with hydrogen peroxide (H2O2), by UV-Visible spectroscopy in diffuse reflectance mode, Raman and FTIR-ATR. The presence of different reaction sites for the NbO7 and NbO8 type systems, which are directly related to the surface defects present in different states of crystallization, was totally characterized. The reactivity of different catalysts obtained from the niobium oxide (V) was investigated using methyl linoleate oxidation in the presence of H2O2 as a probe reaction. The reaction was monitored by GC-MS, as well as by 1 H and 13 C NMR spectrometry, with the dominant product of the reaction being 9-oxo-nonanoic acid methyl ester. Based on these results, a reaction mechanism was proposed involving an auto-oxidation process that initially leads to the formation of hydroperoxides that decompose rapidly via a Hock-like rearrangement, leading to the formation of aldehydes.

MEMBROS DA BANCA:
Presidente - 386645 - AURELIO BAIRD BUARQUE FERREIRA
Interno - 1475121 - MARCELO HAWRYLAK HERBST
Interno - 1115883 - ANTONIO MARQUES DA SILVA JUNIOR
Externo ao Programa - 387116 - HELIO FERNANDES MACHADO JUNIOR
Externo ao Programa - 1488978 - CRISTIANE HESS DE AZEVEDO MELEIRO
Externo à Instituição - RODRIGO JOSÉ CORREA - UFRJ
Externo à Instituição - CARLOS EDUARDO RODRIGUES DE PAULA - UFRJ
Externo à Instituição - ELIZABETH RODITI LACHTER - UFRJ
Externo à Instituição - ANGELA SANCHES ROCHA - UERJ