Electrochemical performance and carbon deposition resistance of M-BaZr(0.1)Ce(0.7)Y(0.1)Yb(0.1)O(3-δ) (M = Pd, Cu, Ni or NiCu) anodes for solid oxide fuel cells

Pd-, Cu-, Ni- and NiCu-BaZr(0.1)Ce(0.7)Y(0.1)Yb(0.1)O(3-δ )anodes, designated as M-BZCYYb, were prepared by impregnating M-containing solution into BZCYYb scaffold, and investigated in the aspects of electrocatalytic activity for the reactions of H(2) and CH(4) oxidation and the resistance to carbon deposition. Impregnation of Pd, Ni or NiCu significantly reduced both the ohmic (R(Ω)) and polarization (R(P)) losses of BZCYYb anode exposed to H(2) or CH(4), while Cu impregnation decreased only R(Ω )in H(2) and the both in CH(4). Pd-, Ni- and NiCu-BZCYYb anodes were resistant to carbon deposition in wet (3 mol. % H(2)O) CH(4) at 750°C. Deposited carbon fibers were observed in Pd- and Ni-BZCYYb anodes exposed to dry CH(4) at 750°C for 12 h, and not observed in NiCu-BZCYYb exposed to dry CH(4) at 750°C for 24 h. The performance of a full cell with NiCu-BZCYYb anode, YSZ electrolyte and La(0.6)Sr(0.4)Co(0.2)Fe(0.8)O(3-δ)-Gd doped CeO(2) (LSCF-GDC) cathode was stable at 750°C in wet CH(4) for 130 h, indicating that NiCu-BZCYYb is a promising anode for direct CH(4) solid oxide fuel cells (SOFCs).