Banca de QUALIFICAÇÃO: JESUS ANTONIO DUARTE GUALTEROS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE: JESUS ANTONIO DUARTE GUALTEROS
DATA: 27/04/2018
HORA: 08:30
LOCAL: Auditório da Química
TÍTULO: Highly Dispersed Gold Nanoparticles on Different Oxides: Template-Free Synthesis for Benzyl Alcohol Oxidation
PALAVRAS-CHAVES: gold nanoparticles, oxidation and benzyl alcohol
PÁGINAS: 27
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
RESUMO:

The benzyl alcohol oxidation was investigated over gold nanoparticles supported on TiO₂, SiO_2, and Al₂O₃, under aerobic conditions. Here, we show that very high catalytic performances (TOF = 443,624 h^-1) were attained for such reaction using 0.08 – 0.05 mol% of gold loading under optimized conditions. The catalysts were prepared by a deposition-precipitation method using urea as the precipitating agent and the reactions were performed in the absence of a solvent. The alcohol oxidation was used as a test reaction to investigate the influence of the metal-support interaction and the catalytic activity and stability of the materials. The conversion of the substrate was found to be particularly associated to the support choice since the Au NPs over the oxides presented similar sizes, as attested by the SEM images, which confirmed well dispersion of the metal on the supports and reproducibility of the method. A sub-stoichiometric quantity of base was sufficient for the catalyst activation and the observation of the catalysts profile over the time enable insights on the recyclability of the systems. The physicochemical proprieties of the catalysts were scrutinized by CO chemisorption, temperature-programmed desorption (TPD), temperature-programmed reduction (TPR), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) method. Also, the total amount of gold on the surfaces of the catalysts was analyzed by flame atomic absorption spectroscopy (FAAS).

MEMBROS DA BANCA:
Presidente - 2363808 - EDMILSON MIRANDA DE MOURA
Interno - 756.483.183-91 - GERALDO EDUARDO DA LUZ JUNIOR - UESPI
Interno - 1714171 - JANILDO LOPES MAGALHAES
Interno - 2351244 - JEAN CLAUDIO SANTOS COSTA
Interno - 317.429.678-17 - MARCO AURELIO SULLER GARCIA - UFPI
Externo à Instituição - LUCAS SAMUEL SOARES DOS SANTOS - UFT