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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Accelerated ceria-zirconia solubilization by cationic diffusion inversion at low oxygen activity

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Author(s):
Esposito, Vincenzo ; Ni, De Wei ; Marani, Debora ; Teocoli, Francesca ; Thyden, Karl Tor Sune ; De Florio, Daniel Zanetti ; Fonseca, Fabio Coral
Total Authors: 7
Document type: Journal article
Source: JOURNAL OF MATERIALS CHEMISTRY A; v. 4, n. 43, p. 16871-16878, 2016.
Web of Science Citations: 9
Abstract

Fast elemental diffusion at the Gd-doped ceria/Y-stabilized zirconia interface occurs under reducing conditions at low oxygen activity (pO(2) < 10(-12) atm) and high temperature (1400 degrees C). This effect leads to formation of thick ceria-zirconia solid solution reaction layers in the micro-range vs. thin layers of few tens of nanometers under oxidative conditions (i.e. in synthetic air at pO(2) = 0.21 atm). The fast dissolution occurs by an inversion of the dominating limiting mechanism from the expected Zr4+ diffusion into the CGO lattice at high pO(2) to an unexpected Ce3+ diffusion into the YSZ component under reducing conditions. The diffusion coefficient of 8-fold coordinated Ce3+ in YSZ at 1400 degrees C and pO(2) = 10(-13) atm is estimated to be around 10(-11) cm(2) s(-1). This value is around 3 orders of magnitude higher than Zr4+ interdiffusion in CGO under oxidative conditions and about 8 orders of magnitude higher than Ce4+ self-diffusion in CGO in air at the same temperature. (AU)

FAPESP's process: 14/50279-4 - Brasil Research Centre for Gas Innovation
Grantee:Julio Romano Meneghini
Support type: Research Grants - Research Centers in Engineering Program
FAPESP's process: 13/26961-7 - Development of anodes for solid oxide fuel cells operating directly on renewable fuels
Grantee:Fabio Coral Fonseca
Support type: Regular Research Grants
FAPESP's process: 15/20434-0 - Development of ceramic nanosheets-based inks for inkjet printing of ultra-thin films for solid oxide cells (SOCS) components
Grantee:Fabio Coral Fonseca
Support type: Research Grants - Visiting Researcher Grant - International