Proton conducting membranes (SrCe0.95Yb0.05O3-x) were prepared in the form of cylindrical disks. The crystal structure of the disks was characterized by XRD and their morphology was examined by SEM. The effect of CO2 partial pressure to the electrode kinetics of SrCe0.95Yb0.05O3-x/Pd was studied at temperatures between 400 and 700 degreesC. A three-electrode single chamber cell was used to obtain current-overpotential curves. The high field approximation of the Butler Volmer equation was used to calculate exchange and limiting current densities. (C) 2004 Elsevier B.V. All rights reserved.