La0.75Sr0.25−xCexCr0.5Mn0.5O3−δ electrode material for symmetric solid oxide fuel cells with H2S-containing fuel

A series of materials La0.75Sr0.25−xCexCr0.5Mn0.5O3−δ (LSCCM, x = 0, 0.1, 0.13 and 0.15) were synthesized by the sol-gel process, and their structures were demonstrated using X-ray diffraction (XRD). The best ratio of ceria-substitution in LSCCM series was studied in detail by H2 temperature programmed reduction (H2-TPR), O2 temperature programmed desorption (O2-TPD), and Fourier transform infrared (FTIR). The catalytic activity results of H2-TPR and O2-TPD prove that ceria-substitution x = 0.15 for La0.75Sr0.25−xCexCr0.5Mn0.5O3−δ has the best catalytic activity, but the FTIR results show the material with high ceria content is not resistant to sulfur. Taking account both catalytic activity and sulfur tolerance, ceria-substitution x = 0.13 is an optimum for La0.75Sr0.25−xCexCr0.5Mn0.5O3−δ, with which maximal power density of 17.86 mW cm−2 can be attained in 5% H2S-5% wet H2 at 900 °C.