International Journal of Hydrogen Energy, Vol.39, No.32, 18379-18384, 2014
The effect of Cr deposition and poisoning on BaZr0.1Ce0.7Y0.2O3-delta proton conducting electrolyte
With the development of chromium tolerant electrode materials, the evaluation of the chromium deposition and poisoning on electrolyte is critical significance for the commercial and widespread application of solid oxide fuel cell stacks (SOFCs). The Cr deposition and poisoning on BaZr0.1Ce0.7Y0.2O3-delta(BZCY) proton conducting electrolyte are initially studied, in order to understand and develop the compatibility for proton conducting SOFC (H-SOFCs). The XRD results imply that Cr2O3 is not chemically compatible with BZCY and BaCrO4 is formed at high temperature above 600 degrees C. To simulate the Cr volatilization from interconnect and poisoning on BZCY surface, the BZCY bar sample is heat-treated in the presence of Cr2O3 at 600 degrees C, 700 degrees C, and 800 degrees C for 50 h. It is clear that Cr deposition occurs even at 600 C by SEM examination. The XPS results indicate the chemical deposition of BaCrO4 and physical deposition of Cr2O3 on BZCY surface at 600 degrees C but only chemical deposition at 700 degrees C and 800 degrees C. The content of Cr deposition increases with the increase of poisoning temperature. Moreover, the proton conductivity of BZCY after Cr deposition reduces after Cr deposition, indicating the Cr poisoning effect of the electrochemical performance of BZCY electrolyte. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.