Electrochemical behaviors of Y-doped La0.7Sr0.3CrO3−δ anode in sulfur-containing fuel SOFC

•Effect of Y as dopant on electro-catalytic activity for LSCY was investigated.•Electro-catalytic activity of LSCY still needs improvements.•EIS indicates polarization loss for LSCY dominates in the total resistance loss.•A hypothesis about choice of doping cation is proposed.

Fuel gas containing sulfur to feed solid oxide fuel cell is a challenge for extending the application of SOFC. Yttrium doped into LaxSr1−xCrO3 as potential anode tolerant to H2S was investigated by XRD, XPS and electrochemical impedance spectra (EIS). Good sinter characteristic for (La,Y)0.7Sr0.3CrO3−δ (LYSC) observed by SEM contributes to the low ohmic loss (high conductivity) in SOFC fueled by H2(3%)–H2S(1%). Maximum power density of 20 mW/cm2 and open circuit voltage of 0.95 V for SOFC with LYSC can be obtained at 700 °C. The results by EIS indicate charge transfer loss in polarization resistance dominates in the total resistance, especially lower than 650 °C. Compared to ohmic loss, polarization resistance in LYSC is still the main cause to hinder the improvement of SOFC performance. Thus, LYSC with doped non-variant valence Y maintains good sulfur tolerance determined by XPS without improved electro-catalytic activity as EIS suggest.

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