Experimentally Validated Simulations of Undoped Ceria Electrodes for H2 Oxidation and H2O Electrolysis in Solid Oxide Electrochemical Cells

We present here the formulation and partial validation of a one-dimensional model of undoped CeO2-x electrodes for H-2 oxidation and H2O splitting in high-temperature solid oxide cells. The model describes dense thin-film electrodes with a porous Au current collector, a dense YSZ supporting electrolyte, and a porous LSM/YSZ composite counter electrode. The model is formulated as a set of differential algebraic equations which are integrated over time to steady-state. Numerical results are compared to V-i curves from single cell tests to yield estimates for important transport, thermodynamic, and kinetic parameters governing electrochemical performance of CeO2-x electrodes in solid oxide cells. These results represent a quantitative framework for the analysis of electrochemical results on ceria electrodes for both H-2 oxidation and H2O electrolysis.