Porous YSZ impregnated with La 0.4 Sr 0.5 Ba 0.1 TiO 3 as a possible composite anode for SOFCs fueled with sour feeds Adrien L. Vincent a , Amir R. Hanifi a , Jing-Li Luo a, * , Karl T. Chuang a , Alan R. Sanger a , Thomas H. Etsell a , Partha Sarkar b a Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2G6 b Environment & Carbon Management Division, Alberta Innovates e Technology Futures, Edmonton, Alberta, Canada T6N 1E4 highlights < The catalytic activity of the anodes increased with the amount of LSBT up to an optimum value. < H 2 S promotes the hydrogen and the methane activation on LSBT. < Impregnation is a better choice for anode preparations than powder mixtures. < The fuel mixture Methane H 2 S, can provides a very high power density compared to respective single gases. < The impregnation process allows construction of anode supported SOFC membranes. article info Article history: Received 24 February 2012 Received in revised form 19 April 2012 Accepted 20 April 2012 Available online 18 May 2012 Keywords: SOFC Porous YSZ Microstructure La 0.4 Sr 0.5 Ba 0.1 TiO 3 Impregnation Perovskite abstract The system LSBT/YSZ (LSBT is La 0.4 Sr 0.5 Ba 0.1 TiO 3 ) is a promising combination as an anode material for full ceramic SOFCs. An anode comprising a porous layer of YSZ impregnated with LSBT shows good performance for conversion of high sulfur content fuels. The microstructures within the composite matrix were determined and correlated with the parameters of the production process. The anodes were characterized electrochemically using impedance spectroscopy (EIS) and potentiodynamic tests per- formed at 850  C with various fuels to determine the effect of H 2 S in the feeds: H 2 ,H 2 /H 2 S (5000 ppm), CH 4 , CH 4 /H 2 S (5000 ppm). The highest power densities (200 mW cm 2 in H 2 /H 2 S) were obtained for LSBT/YSZ composites after impregnation six times with LSBT, corresponding to 12.6 wt% LSBT; further impregnations dramatically decreased performance as a result of restricted access of fuel to active sites. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction A major source of interest in solid oxide fuel cells (SOFCs) arises from their theoretical capability to use any oxidizable feed as fuel. Unfortunately, several prospective catalyst materials presently used in anodes are readily poisoned by one or more possible impurities in anode feed gases [1e3]. Hence, the current generation of commercial SOFCs typically operates on pure hydrogen, an expensive feed, to ensure both good performance and good stability [4,5]. The majority of industrial H 2 is manufactured by conversion of hydrocarbon resources, for example, by steam reforming. Major anode catalyst poisons present in fuels derived from coal or lighter hydrocarbons are CO and H 2 S. While it is possible to oxidize H 2 S as a fuel [6,7], the most efficient H 2 SOFC catalysts, notably Pt, Pd and the cermet Ni-YSZ, react rapidly with H 2 S either to form a sulfide or to poison the catalyst surface, even at low concentrations [8]. Therefore, one of the main challenges in development of new SOFCs is to enhance the stability of the anode in the presence of H 2 S. Recently, it was shown that lanthanum strontium titanate [9e12] (LST, La x Sr y TiO 3 ) is a promising anode material. In H 2 eair fuel cells the performance of LST anodes was shown to be compa- rable (in its initial state) with that obtained from the widely used cermet Ni/YSZ [13]. Additionally, LST appeared to be stable under a reducing environment containing H 2 S [14] and the presence of * Corresponding author. Tel.: þ1 780 492 2232. E-mail address: jingli.luo@ualberta.ca (J.-L. Luo). Contents lists available at SciVerse ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour 0378-7753/$ e see front matter Ó 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.jpowsour.2012.04.063 Journal of Power Sources 215 (2012) 301e306