Degradation phenomena of Ni0.5Cu0.5-CGO (Ce0.8Gd0.2O1.9) bimetallic anode in different concentrations of dry methane were studied in LSM ((La0.75Sr0.25)(0.95)MnO3-delta)-CGO cathode supported SOFCs. According to XRD, SEM and EIS analyses, the degradation of the Ni0.5Cu0.5-CGO bimetallic anode could be mainly attributed to re-oxidation of Ni by H2O and/or by rapid sintering of Ni due to a high p(H2O) appeared at a high current density. Furthermore, it is found that the degradation of anode resulted by the re-oxidation of Ni and/or by rapid sintering of Ni in the as-prepared cells generally occurred when the partial pressure ratio of the produced H2O and CH4 at the outlet of anode increased above a threshold value in different concentrations of dry methane. (C) 2011 Elsevier Ltd. All rights reserved.