Preparation and characterization of Pr2NiO4+δ infiltrated into Gd-doped ceria as SOFC cathode

Composite electrodes of Pr2NiO4+delta and Gd-doped ceria (Ce0.8Gd0.2O1.90 so-called GDC) have been prepared starting from a Pr-Ni nitrate solution (2:1 stoichiometry ratio) that was infiltrated into a porous GDC backbone made by screen printing onto 3 % yttria-stabilized zirconia membrane (90 mu m thick). The crystallization of the Pr2NiO4+delta powder was first studied by X-ray diffraction: it highly depends on the annealing atmosphere (air or N-2) and the formation of this phase as infiltrate is more difficult than for the powder. The electrochemical study performed on symmetrical cells shows that the polarization resistance decreases when the annealing temperature of the infiltrate electrode decreases. The lowest R (p) value is obtained for an annealing at 900 A degrees C, for 2 h in N-2, the value being 0.075 Omega cm(2) at 600 A degrees C in air.