Banca de DEFESA: ANTONIO TEOFANES BERTOLLO DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANTONIO TEOFANES BERTOLLO DE OLIVEIRA
DATE: 06/09/2023
TIME: 14:00
LOCAL: Sala 307 do Bloco B do Campus de Santo André da Universidade Federal do ABC
TITLE:

Lanthanum Strontium Titanate doped with Copper and Nickel:
synthesis, characterization and nanoparticles exsolution for

solid oxide fuel cell electrodes

PAGES: 98
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:

Climate emergency has become the most significant concern of the century due
to the 1.5 oC increase in the average atmospheric temperature, resulting in a
profound impact on natural events. In recent years, considerable efforts have
been directed towards achieving net-zero emissions, primarily through the
substitution of fossil fuels with decarbonization. Solid oxide fuel cells (SOFCs)
are devices that efficiently convert chemical energy into electrical energy, offering
fuel flexibility and generating low to zero CO2 emissions. Due to these features,
SOFCs are considered a promising alternative. SOFC anodes play a crucial role
in catalyzing fuel oxidation. Among the materials used for this purpose, ceramic

perovskites stand out as excellent electrodes due to their high mixed ionic-
electronic conductivity, chemical and thermal stabilities, and strong catalytic

properties. In this study, our focus is on obtaining exsolved metal alloy
nanoparticles anchored to perovskite structures, exploring a more promising,
challenging, and less explored material in the existing literature.
La0.8Sr0.2Ti0.7Ni0.3-xCuxO3-δ (x = 0.1, 0.15, 0.2) and La1.2Sr0.7Ni0.5Cu0.5O4 samples
were obtained through the Pechini synthesis route and were calcined at 900 °C

for 5 hours. The production of decorated NiCu nanoparticles involved heat-
treating the powders in a 3 vol % H2/N2 atmosphere at 900 oC for 10 hours. The

samples were subjected to various characterization techniques, including
thermogravimetry (TG/DTA), dilatometry, scanning electron microscopy (SEM),
transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray
photoelectron spectroscopy (XPS), and electrochemical impedance
spectroscopy (EIS). XRD and XPS analyses confirmed the successful formation
of NiCu alloy particles using the chosen synthesis route and the reduction
treatment. Structural parameters such as crystal symmetry, crystallite size, and
phase content were determined using Rietveld's refinement. SEM revealed the
presence of spherical nanoparticles anchored on the sample surface, and TEM
confirmed the composition of copper-nickel alloy nanoparticles. Finally, EIS
revealed that La0.8Sr0.2Ti0.7Ni0.15Cu0.15O3-δ exhibited the highest conductivity of
8.06 x 10-3 S cm-1

in air atmosphere at 961 K.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1545089 - DANIEL ZANETTI DE FLORIO
Membro Titular - Examinador(a) Interno ao Programa - 1545738 - MARCIA TSUYAMA ESCOTE
Membro Titular - Examinador(a) Externo à Instituição - CRISTIANE BARBIERI RODELLA - CNPEM
Membro Suplente - Examinador(a) Interno ao Programa - 2605463 - JOSE ANTONIO SOUZA
Membro Suplente - Examinador(a) Externo à Instituição - FÁBIO CORAL FONSECA - IPEN