Technical Communication Silver modified cathode for a micro-tubular, single-chamber solid oxide fuel cell Naveed Akhtar*, Kevin Kendall Department of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK article info Article history: Received 30 July 2010 Received in revised form 26 September 2010 Accepted 11 October 2010 Available online 16 November 2010 Keywords: Solid oxide fuel cell Single-chamber Silver Structural Micro-tubular abstract Micro-tubular, solid oxide fuel cells consisting of nickel, yttria-stabilized zirconia (NieYSZ) anode, yttria-stabilized zirconia (YSZ) electrolyte and lanthanum strontium cobaltite fer- riteegadolinium doped ceria (LSCFeGDC) cathode have been developed and operated under single-chamber conditions, utilizing methane/air mixture. The cell performance was compared with a silver modified cathode by the addition of 10wt% silver-paste in LSCFeGDC cathode. The cells with and without silver addition yielded maximum power densities of 118.75 mW cm 2 and 61.53 mW cm 2 at 700  C, respectively. The results demonstrate that silver is a good candidate for enhancing the oxidation reduction kinetics via improved adsorption, desorption, dissociation and subsequent diffusion. However, long term performance of the silver modified cathode is not guaranteed under single-chamber conditions. ª 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved. 1. Introduction In recent years there has been an increasing interest in the research and development of single-chamber, solid oxide fuel cells (SC-SOFCs) [1e4]. Though, SC-SOFCs are an ideal candi- date for portable type applications where normally low power densities are demanded, they offer compact design due to elimination of gas-separating channels and are very simple to fabricate [2,3]. Furthermore, gas-tight sealing is not required because the reactants are already pre-mixed. Besides these advantages, they still have to suffer many challenges such as, low fuel-utilization/electrical efficiencies, high catalytic/elec- tro-catalytic activity and selectivity of the electrodes for their respective reactions (e.g. anode must maintain high activity for partial oxidation followed by electrochemical oxidation of the produced species such as carbon monoxide and hydrogen; cathode must be inert towards fuel combustion). Moreover, all of the components (i.e. the anode, cathode, electrolyte and interconnects) must be durable enough to work properly in a dual-atmospheric environment. Not only this, the extremely low power densities of SC-SOFCs put further restrictions on their use, as such, at present they are suitable for miniaturized portable power generations, only [3,5e12]. The purpose of this study is to focus on one of the above listed challenges, i.e. to suggest possible ways to improve the power densities of SC-SOFCs. In this respect, cathode side improvement was opted due to the well-established reason that the cathode overpotential accounts for the major power loss in a solid oxide fuel cell (SOFC) operation [13]. The state of the art, conventional cathode (i.e. lanthanum strontium * Corresponding author. Present address: Department of Chemical Engineering and Chemistry, Technical University Eindhoven, 5600 MB, Eindhoven, The Netherlands. E-mail address: navtar433@yahoo.com (N. Akhtar). Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 36 (2011) 773 e778 0360-3199/$ e see front matter ª 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ijhydene.2010.10.043