abstract
Ceria-based composites (50 vol% of the ceramic phase) including one mixture of Li and Na carbonates (1:1 molar ratio), were prepared using either pure ceria (modest conductor) or Gd-doped ceria (excellent oxide ion conductor) as ceramic matrix. These materials were aged for periods of up to 1000 h at 550 degrees C, under pure CO2, in air and in H-2 diluted in N-2, to test their stability and electrical performance. Impedance spectroscopy measurements performed between 300 and 600 degrees C were complemented by structural and microstructural characterization. The excellent long-term stability in CO2 drops slightly when moving to air and in a pronounced manner when moving to diluted H-2. In all cases and in all conditions the best performance is observed for pure ceria-based composites. Electrode (Au) and electrolyte degradation were found interrelated. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
keywords
PERCENT EUTECTIC MIXTURE; DOPED-CERIA; MOLTEN-CARBONATE; IMPEDANCE SPECTROSCOPY; ITSOFC APPLICATIONS; 973 K; PERFORMANCE; BEHAVIOR; DIOXIDE; OXIDE
subject category
Chemistry; Electrochemistry; Energy & Fuels
authors
Rondao, AIB; Patricia, SG; Figueiredo, FML; Marques, FMB
our authors
Ana Inês Batista Lourenço Rondão
Post-Doc Fellowship
Fernando Manuel Bico Marques
Full professor
Filipe Miguel H Lebre R Figueiredo
Principal ResearcherProjects
NANOCELL - Nanocomposite Electrolytes for Intermediate Temperature Fuel Cells (PTDC/CTM/098486/2008)
acknowledgements
Financial support from Project NANOCELL (PTDC/CTM/098486/2008), CICECO (PEst-C/CTM/LA0011/2013), FCT/COMPETE, FEDER (Portugal) is greatly appreciated. S Patricio thanks FCT for the post-doctoral grant (BPD/75943/2011).