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

Autor(es)

Esposito, Vincenzo ; Ni, De Wei ; Marani, Debora ; Teocoli, Francesca ; Thyden, Karl Tor Sune ; De Florio, Daniel Zanetti ; Fonseca, Fabio Coral

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MATERIALS CHEMISTRY A; v. 4, n. 43, p. 16871-16878, 2016.
• Citações Web of Science: 13

Resumo

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)

• Processo FAPESP: 13/26961-7 - Desenvolvimento de ânodos de células a combustível de óxidos sólidos operando diretamente com combustíveis renováveis
• Beneficiário: Fabio Coral Fonseca
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 15/20434-0 - Desenvolvimento de tintas cerâmicas baseadas em nanofolhas para impressão jato de tinta de camadas ultrafinas de componentes de células de óxidos sólidos (SOCs)
• Beneficiário: Fabio Coral Fonseca
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional