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Previous issue date: 2015-06-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O PSFC (Pr0.5Sr0.5Fe1-xCuxO3-?) ? um novo ?xido misto com estrutura perovskita que
vem sendo estudado para aplica??o como catodo de c?lulas a combust?vel de ?xido
s?lido de temperatura intermedi?ria (600-750 ?C), principalmente devido a sua
elevada condutividade i?nica e eletr?nica abaixo de 800 ?C. Neste trabalho, p?s de
PSFC com duas composi??es diferentes (Pr0,5Sr0,5Fe0,8Cu0,2O3-PSFC5582 e
Pr0,5Sr0,5Fe0,6Cu0,4O3-PSFC5564) foram sintetizados pelo m?todo dos citratos
utilizando uma nova rota. Os p?s obtidos foram caracterizados por an?lise t?rmica
(Termogravimetria e Calorimetria Diferencial Explorat?ria), e os materiais calcinados
a 800, 900 e 1000 ?C por 5h foram analisados por difratometria de raios X (DRX),
com refinamento Rietveld dos dados de difra??o e dilatometria. Filmes de
composi??o PSFC5582 foram obtidos por serigrafia do p? calcinado a 1000 ?C. Os
filmes foram depositados em substrato de c?ria dopada com gadol?nia (CGO) e
sinterizados a 1050 ?C por 2h. O desempenho eletroqu?mico dos eletrodos foi
avaliado por espectroscopia de imped?ncia e a interface eletrodo/eletr?lito foi
observada por microscopia eletr?nica de varredura (MEV). A resist?ncia espec?fica
por ?rea (ASR) foi 0,44 ?.cm? a 800 ?C, um valor pouco inferior aos reportados na
literatura para catodos contendo cobalto. Os coeficientes de expans?o t?rmica (CET)
do PSFC de ambas as composi??es variaram entre 13 e 15 x 10-6 ?C-1
, numa faixa
de temperatura de 200 a 650 ?C, demonstrando a boa compatibilidade t?rmica
destes catodos com eletr?litos de Ce0,9Gd0,1O1,95 (CET = 12 x 10-6
?C). / The PSFC (Pr0.5Sr0.5Fe1-xCuxO3-?) is a new mixed oxide perovskite and has been
studied and evaluated the cathode materials for intermediate temperature solid oxide
fuel cells (IT-SOFCs), mainly due to its good compatibility with the electrolyte (CGO)
and its high ionic conductivity and electronic in intermediate temperature. In this
work, PSFC powders with two different compositions (Pr0,5Sr0,5Fe0,8Cu0,2O3-
PSFC5582 and Pr0,5Sr0,5Fe0,6Cu0,4O3-PSFC5564) were synthesized by the citrate
method using a new route. The powders obtained were characterized by thermal
analysis (Differential Scanning Calorimetry and Thermogravimetry), and the material
calcined at 800, 900 and 1000 ?C for 5h were analyzed by X-ray diffractometry
(XRD), with the Rietveld refinement of the diffraction data and dilatometry.
PSFC5582 composite films were obtained by screen printing of powder calcined at
1000 ?C. The films were deposited on substrate ceria doped with gadolinia (CGO)
and then sintered at 1050 ?C for 2h. The electrochemical performance of the
electrodes was evaluated by impedance spectroscopy and the interface
electrode/electrolyte was observed by scanning electron microscopy (SEM). The
specific resistance area (ASR) was 0.44 ?.cm? at 800 ?C, slightly lower than those
reported in the literature for cathodes containing cobalt. The thermal expansion
coefficients of both the PSFC compositions were obtained and varied between 13
and 15 x 10-6
?C-1
, in a temperature range of 200 to 650 ?C, demonstrating the good
thermal compatibility of cathodes with Ce0,9Gd0,1O1,95 electrolytes (CET = 12 x 10-6
?C).
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/20152 |
| Date | 25 June 2015 |
| Creators | Moura, Caroline Gomes |
| Contributors | 80732810400, http://lattes.cnpq.br/8671649752936793, Miranda, Auristela Carla de, 03501789416, http://lattes.cnpq.br/1311586220144057, Macedo, Daniel Ara?jo de, 01152094416, http://lattes.cnpq.br/1027496814443777, Aquino, Fl?via de Medeiros, 05660333486, http://lattes.cnpq.br/5822416945469021, Nascimento, Rubens Maribondo do |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM CI?NCIA E ENGENHARIA DE MATERIAIS, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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