Redox stability and sulfur resistance of Sm0.9Sr0.1CrxFe1−xO3−δ perovskite materials

• The redox and sulfur stability of SSCF was examined firstly.
• These materials have tendency to recapture oxygen when exposed to air after reduction.
• There is no other work report the role of lattice oxygen in deactivation of SSCF.

Sm0.9Sr0.1Cr0.5Fe0.5O3−δ was used as a promising anode catalyst for the conversion of H2S-containing fuel by SOFC in our previous research. A further research about the redox stability and sulfur resistance of the series of Sm0.9Sr0.1CrxFe1−xO3−δ (x = 0.2, 0.5, 0.8) was carried out through XRD, TEM, BET, and H2-TPR in this work. It was found the different doping amount of SSCF were stable at the temperature below 800 °C under reduction conditions. XPS was used to compare the fresh sample with the treated one. The reduction treatment tended to decrease the concentration of lattice oxygen but the surface adsorbed oxygen amount was found to be higher in reduced samples comparing with fresh samples. It was suggested that these materials had tendency to recapture oxygen when exposed to air after reduction. The role of lattice oxygen in deactivation of SSCF as anode catalyst was also studied after the sample was reduced to 1000 ppm H2S (balanced by N2) at 800 °C for 2 h.

The Sm0.9Sr0.1Cr0.5Fe0.5O3−δ is demonstrated to be a potential anode material for SOFCs running on H2S-containing fuel in our previous research, so in this work we synthesized a series of perovskite materials with formula Sm0.9Sr0.1CrxFe1−xO3−δ. XRD, XPS, TEM, BET, and H2-TPR were used to study the resulting perovskites in terms of their redox stability of both bulk and H2S stability. The role of lattice oxygen in deactivation of SSCF as anode catalyst was also studied.Figure optionsDownload as PowerPoint slide