Investigation of Ce0.9Sr0.1Cr0.5Co0.5O3−δ as the anode material for solid oxide fuel cells fueled with H2S

Ce0.9Sr0.1Cr0.5Co0.5O3−δ (CSCrCo) as an anode catalyst was studied in a solid oxide fuel cell (SOFC), where hydrogen sulfide (H2S) was used as fuel. The conductivities were evaluated with a four-probe DC technique in 3 % H2-N2 and 5 % H2S-N2 at 570–800 °C, respectively. X-ray diffraction (XRD) patterns show that CSCrCo powders are fluorite structure which is similar to that of CeO2 parent (JCPDS card no. 34-0394). Meanwhile, CSCrCo anode material has good chemical compatibility with electrolyte (Ce0.8Sm0.2O1.9 (SDC)) in N2. Through the analysis of XRD and Fourier transform infrared patterns, no other new phase is detected after treatment in 5 % H2S-N2 at 800 °C for 5 h, which indicate that the material has a good sulfur tolerance. H2 temperature-programmed reduction and Tafel curves indicate that the temperature of the best catalytic activity is 600 °C. The electrochemical properties of the cell comprising CSCrCo-SDC/SDC/Ag are measured in 5 % H2S-N2 at low temperatures (500 and 600 °C). The maximal open circuit voltage is 1.04 V, the maximal power density is 12.55 mW cm−2, and the maximal current density is 40 mA cm−2 at 500 °C. While at 600 °C, the corresponding values are 0.95 V, 14.21 mW cm−2, and 90.01 mA cm−2, respectively. After SOFC operating in 5 % H2S, X-ray photoelectron spectroscopy is used to compare the fresh sample with the H2S-treated one.