. . . . . . . . . .    ANM 2010     3rd International Conference on Advanced Nano Materials     12-15 September 2010 - Agadir, Morocco Back    Abstract ANMM336 COMPUTATIONAL MODELING OF DEGRADATION ISSUES IN SOLID OXIDE FUEL CELL ELECTRODES M.A. Khaleel, E.M. Ryan, K.P. Recknagle Pacific Northwest National Laboratory, Richland, WA USA . In this presentation we will discuss a multi-scale modeling approach to investigate contaminants and degradation issues in the electrodes of solid oxide fuel cells (SOFCs). The complex multi-physics of SOFCs occur at various spatial and temporal scales ranging from the nano-scale surface reactions of the electrochemistry to the macro-scale thermal gradients across stacks of SOFCs. To study the effects of degradation mechanisms on the whole SOFC system a multi-scale modeling approach is needed which couples modeling tools at various scales to better understand the fundamental mechanisms causing degradation and to help guide developers in mitigating degradation. As part of this research several different modeling tools are being developed including atomic level modeling of the adsorption of small molecules on the electrode surfaces, pore-scale modeling of the reactive transport of contaminants in the electrodes, and cell level modeling of the electrochemistry through the electrodes and electrolyte. In this talk we will discuss these models and how they fit into a multi-scale modeling framework to investigate degradation issues. Detailed discussion of the pore-scale model will also be included covering the development of a novel Lagrangian reactive transport model, which discretely models the microstructure of the porous electrodes to resolve the local surface reactions of contaminants with the electrode. The 3D pore-scale model includes the transport of species in the electrodes through gas and surface diffusion and the reactions of species with the electrode surface via competitive adsorption. The model is applied to the degradation of the SOFC cathode due to chromium poisoning, which reduces the electrochemical activity of the cathode due to the adsorption of chromium species on the cathode surface. . © nanoAC . . . . . . . . . .

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