| The oxides with perovskite type structure received much attention due to their structure stability in broad range of oxygen pressure and temperature. The substituted compounds may show mixed oxygen ionic and electronic conducting performance, which has catalytic action to fuel's oxidation. Pudmich et al have examined LaCrO3 - based perovskites as potential anode materials of SOFCs. In order to extend this research, the feasibility of SmCrO3- based perovskite as anode material is investigated in this work.SmCrO3 was substituted to improve its electrochemical and catalytic performance. The results are summarized in below: all materials studied are stable in reducing atmosphere, and have good compatibility with YSZ. Ca2+and Sr2+ doped in a position improves the conductivity of this material, and the conductivity increase two orders in magnitude in reducing atmospheres. Meanwhile, the anode polarization resistances decrease. The material's catalytic performance was further improved with manganese ion doping in B position, and the polarization resistances are greatly decreased. The polarization resistance of Sm0.75Sr0.25Cr0.5Mn0.5O3 is about 9.6Ωcm2 at 800°C in5% H2. The effects of cation vacancy in A site and the variation of anode thickness on the material's performance are further studied. The results indicate that with the increase of anode thickness, the polarization resistance decrease first, and then increase. It has a minimum value in appropriate thickness. Vacancy of Sm3+ changes the conductivity and decreases the polarization resistance. The polarization resistance of Sm0.8Cr0.5Mn0.5O3 is about 10.13Ωcm2 at 800°C in 5% H2. |
