An optimization of the oxygen electrode microstructure needs to be addressed to improve the performance of solid oxide fuel cell (SOFC) since the kinetics of the oxygen reduction reactions (ORR) in the cathode remains the main limiting factor. In this work, the electrochemical properties of the Pr6O11 architectured electrode are investigated as a function of the microstructure of the active functional layer (AFL) prepared by electrostatic spray deposition (ESD) on Ce0.9Gd0.1O2-delta (GDC) electrolyte. An optimization of the AFL microstructure is investigated varying sintering temperature from 600 degrees C to 1000 degrees C for 2 h in air. The effect of sintering temperature on the AFL microstructures is visualized and discussed thanks to FIB/SEM (focus ion beam/scanning electron microscopy) reconstructions. The composition and thickness of a CCL current collecting layer (CCL), deposited by screen-printing (SP) on the top of this AFL, are optimized as well. The nature of the CCL is either Pr6O11, La0.7Sr0.3MnO3-delta (LSM) or La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) and the thickness is varied from 15 to 60 mu m. Moreover, the compatibility of the Pr6O11 electrode with GDC is checked over 10 days in air at 800 degrees C.