Polarization study of FejBaCe 0.5 Zr 0.3 Y 0.08 Yb 0.08 Cu 0.04 O 3-d jFe electrochemical cells in wet H 2 atmosphere Stratigoula Mitri a , Dmitry Medvedev b,c , Sotiria Kontou a , Elena Gorbova b , Anatoly Demin b , Panagiotis Tsiakaras a,b,* a Laboratory of Alternative Energy Conversion Systems, Department of Mechanical Engineering, School of Engineering, University of Thessaly, Pedion Areos, 383 34 Volos, Greece b Laboratory of Electrochemical Devices Based on Solid State Proton Electrolytes, Institute of High Temperature Electrochemistry, 620990 Yekaterinburg, Russia c Department of Environmental Economics, Ural Federal University, 620002 Yekaterinburg, Russia article info Article history: Received 25 February 2015 Received in revised form 11 April 2015 Accepted 4 May 2015 Available online xxx Keywords: Proton conductor Perovskite Solid electrolyte IT-SOFCs Polarization study abstract In the present work, the steady-state current-overpotential characteristics of the FejBaCe 0.5 Zr 0.3 Y 0.08 Yb 0.08 Cu 0.04 O 3-d jFe interface as a function of the gas phase composition and temperature are investigated. To this purpose a BaCe 0.5 Zr 0.3 Y 0.08 Yb 0.08 Cu 0.04 O 3ed dense ceramic material is successfully synthesized by solid state synthesis and sintered at 1400  C. Then its crystal structure, ceramic and electrical properties are investigated. It is found that the ceramic has a high relative density (more than 90%) and acceptable proton conductivity (1.5 and 6.8 mS cm 1 at 500 and 900  C, respectively). On the as prepared BaCe 0.5 Zr 0.3 Y 0.08 Yb 0.08 Cu 0.04 O 3ed electrolyte disk, three thin Fe porous layers are deposited by painting on both sides (three electrode system), which is then immersed in a tubular single-chamber continuous electrochemical reactor. The polarization measurements are carried out in the temperature range between 500 and 700  C and at three different H 2 /He wet (3% steam) compositions. The apparent anodic and cathodic charge transfer coefficients (Tafel region) are found to be: a a ¼ a c ¼ 0.8, while the apparent activation energy is calculated to be approximately 0.55 ± 0.05 eV. It is also found that by increasing the hydrogen concentration the current density increases, espe- cially at higher temperature values. Copyright © 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Introduction Many oxide materials have been used as proton electrolytes [1] in a wide range of solid oxide electrochemical devices including hydrogen and water sensors and pumps, electro- lyzers, electrochemical reactors and fuel cells [2e5]. Further- more, it has been reported that at low and intermediate temperatures, some oxide materials may dissolve significant concentrations of protons when exposed to environments * Corresponding author. Laboratory of Alternative Energy Conversion Systems, Department of Mechanical Engineering, School of En- gineering, University of Thessaly, Pedion Areos, 383 34 Volos, Greece. Tel.: þ30 24210 74065; fax: þ30 24210 74050. E-mail address: tsiak@uth.gr (P. Tsiakaras). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2015) 1 e7 http://dx.doi.org/10.1016/j.ijhydene.2015.05.020 0360-3199/Copyright © 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Mitri S, et al., Polarization study of FejBaCe 0.5 Zr 0.3 Y 0.08 Yb 0.08 Cu 0.04 O 3-d jFe electrochemical cells in wet H 2 atmosphere, International Journal of Hydrogen Energy (2015), http://dx.doi.org/10.1016/j.ijhydene.2015.05.020