Ce0.9Sr0.1Cr0.5Mn0.5O3-δ as the anode materials for solid oxide fuel cells running on H2 and H2S

Perovskite-type Ce0.9Sr0.1Cr0.5Mn0.5O3-delta, (CSCMn) was synthesized and evaluated as anode for solid oxygen fuel cells based on Ce0.8Sm0.2O1.9 (SDC). The conductivities of CSCMn were evaluated with DC four-probe method in 3% H-2-N-2 and 5% H2S-N-2 at 450-700 degrees C, respectively. The compositions of CSCMn powders were studied by XRD and thermodynamic calculations. Meanwhile, sintering temperatures affecting phases of CSCMn is also proposed with XRD, and the analysis is given with thermodynamic calculations. CSCMn exhibits good chemical compatibility with electrolyte (SDC) in N-2. After exposure to 5% H2S-N-2 for 5 h at 800 degrees C, CSCMn crystal structures change and some sulfides are detected, as evidenced by XRD and Raman analyses. The electrochemical properties are measured for the cell comprising CSCMn- SDC/SDC/Ag in 5% H2S-N-2 at 600 degrees C and in 3% H-2-N-2 at 450 and 500 degrees C. The electrochemical impedance spectrum (EIS) is used to analyze ohm and polarization resistance of the cell at various temperatures.