NATALIA KONDO MONTEIRO
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
Artigo IPEN-doc 24469 Low temperature synthesis and properties of gadolinium-doped cerium oxide nanoparticles2017 - MACHADO, M.F.S.; MORAES, L.P.R.; MONTEIRO, N.K.; ESPOSITO, V.; FLORIO, D.Z. de; MARANI, D.; FONSECA, F.C.Gadolinium-doped cerium oxide (GDC) is an attractive ceramic material for solid oxide fuel cells (SOFCs) both as the electrolyte and in composite electrodes operating at low and intermediate temperatures. GDC exhibits high oxygen ion conductivity at a wide range of temperatures and displays a high resistance to carbon deposition when hydrocarbons are used as fuels. However, an inconvenience of ceria-based oxides is the high sintering temperature needed to obtain a fully dense ceramic body. In this study, a green chemistry route for the synthesis of 10 mol% GDC nanoparticles is proposed. The aqueous precipitation method starts from the nitrates of both cerium and gadolinium and uses excess hexamethylenetetramine (HMT) to produce crystalline GDC at 80 ĀŗC. Such a low temperature synthesis provides control over particle size and sinterability of the material at low temperatures.Artigo IPEN-doc 24468 Synthesis of Ru-doped double perovskite anode for SOFC2017 - MONTEIRO, N.K.; CANDIDO, G.A.S.; FONSECA, F.C.Pr0.5Ba0.5MnO3 was studied as the precursor phase of the double perovskite PrBaMn2O5+Ī“ (PBMO) anode material for solid oxide fuel cells (SOFC). The general properties were studied in both the pristine compound and Ru-doped samples Pr0.5Ba0.5Mn1-xRuxO3 (PBMRu). Ru substitution at the B-site is expected to enhance the catalytic properties of the ceramic towards ethanol or methane fuels. The studied compounds were synthesized by the polymeric precursor method and characterized by thermogravimetric analyses, X-rays diffraction (XRD), and electrical transport properties. The experimental data show PBMO phase formation occurring at ~800Ā°C and single phase compounds at ~1100Ā°C up to ~10 at.% of Ru substituted. Similar ionic radius of Ru3+ and Mn3+ results in little effect on both the crystalline structure and electrical conductivity as compared to the pristine compound.Artigo IPEN-doc 17410 Ceramic oxide anode with precipitated catalytic nanoparticles for ethanol fueled SOFC2011 - MONTEIRO, N.K.; NOBREGA, S.D.; FONSECA, F.C.