Ni-YSZ cermet is commonly used as the anode of a solid oxide fuel cell (SOFC) because it has excellent electrochemical performance and is a cost effective anode material for coal-syngas fuel. However, coal-syngas contains trace contaminants, such as phosphine (PH3), hydrogen sulfur (H2S), arsine (AsH3) and stibine (SbH3), and these can cause degradation of the SOFC. Ni-YSZ anode-supported SOFCs were exposed to syngas and H2 fuel, while co-feeding PH3 and chlorine Cl2 impurities under a constant current load at 800°C. The cell degradation was postponed in syngas and highly mitigated in H2. In another test, a Ni-based filter was used to remove the PH3 impurity. The results show that the filter can effectively remove 20 ppm PH3 to a level which does not significantly degrade the SOFC over 400 h. The poisoning effects were evaluated by current-voltage scans and impedance spectroscopy, in addition to thermodynamic and chemical analyses. The post-mortem analyses of the cell and filter were performed by means of XRD and SEM/EDS.

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