A fundamental study of chromium deposition on solid oxide fuel cell cathode materials

Abstract Chromium contamination of metal oxides and SOFC cathode catalysts is studied in the range 700–1000 °C. Samples are exposed to a moist air atmosphere saturated with volatile Cr species in the presence and absence of direct contact between the sample and ferritic stainless steel powder. Chromium contamination of the samples is observed to occur via two separate pathways: surface diffusion from the stainless steel surface and vapor deposition from the atmosphere. Surface diffusion dominates in all cases. Surface diffusion is found to be a significant source of Cr contamination for LSM and LSCF at 700, 800, and 1000 °C. Vapor deposition of Cr onto LSCF was observed at each of these temperatures, but was not observed for LSM at 700 or 800 °C. Comparison of the behavior for LSM, LSCF, and single metal oxides suggests that Mn and Co, respectively, are responsible for the Cr contamination of these catalysts.

[1]  V. Birss,et al.  Chromium Poisoning of LSM-YSZ SOFC Cathodes I. Detailed Study of the Distribution of Chromium Species at a Porous, Single-Phase Cathode , 2004 .

[2]  S. Badwal,et al.  Interaction between chromia forming alloy interconnects and air electrode of solid oxide fuel cells , 1997 .

[3]  Taniguchi Shunsuke,et al.  Degradation phenomena in the cathode of a solid oxide fuel cell with an alloy separator , 1995 .

[4]  Bartley B. Ebbinghaus,et al.  Thermodynamics of gas phase chromium species: The chromium oxides, the chromium oxyhydroxides, and volatility calculations in waste incineration processes , 1993 .

[5]  J. Fergus.  Metallic interconnects for solid oxide fuel cells , 2005 .

[6]  Lorenz Singheiser,et al.  Vaporisation of chromia in humid air , 2005 .

[7]  D. Peck,et al.  Chromium Vapor Species over Solid Oxide Fuel Cell Interconnect Materials and Their Potential for Degradation Processes , 1996 .

[8]  Y. Matsuzaki,et al.  Dependence of SOFC Cathode Degradation by Chromium-Containing Alloy on Compositions of Electrodes and Electrolytes , 2001 .

[9]  Y. Zhen,et al.  A fast method for the investigation of the interaction between metallic interconnect and Sr-doped LaMnO3 of solid oxide fuel cells , 2005 .

[10]  San Ping Jiang,et al.  A comparative investigation of chromium deposition at air electrodes of solid oxide fuel cells , 2002 .

[11]  P. Decorse,et al.  A comparative study of the surface and bulk properties of lanthanum-strontium-manganese oxides La1−xSrxMnO3±δ as a function of Sr-content, oxygen potential and temperature , 1999 .

[12]  M. Mogensen,et al.  X-ray diffraction investigation of phase stability in the Co-Cr-O and the Fe-Co-Cr-O systems in air at 1323 K , 2005 .

[13]  L. Jian,et al.  Electrical and microstructural characterization of spinel phases as potential coatings for SOFC metallic interconnects , 2006 .