Sr0.85Ce0.15Fe0.67Co0.33O3-? IT-SOFC cathodes prepared by solution combustion synthesis: effect of the combustion fuel mixture

Introduction Doped SrFeO3 perovskite-type oxides have been already studied as cathodes for Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFCs) [1,2]. In particular, Ce and Co are suitable doping elements in these compounds. Synthesis methods to obtain these materials are various and can influence their performances. In this work, Sr0.85Ce0.15Fe0.67Co0.33O3-? samples were prepared by Solution Combustion Synthesis (SCS), using different combustion fuels, in order to evaluate their effect on the desired materials features and performances [3]. Materials and methods Syntheses were carried out by SCS between metal nitrates (oxidizers) and different combustion fuels (reducers), namely citric acid, sucrose, sucrose+PEG1000 (1:1) and sucrose+PEG20000 (1:1). The materials were characterized through Temperature-time profiles, X-Ray Diffraction coupled with Rietveld Refinements, Thermogravimetric Analysis (TGA), Nitrogen adsorption, Temperature Programmed Reduction (TPR) and Electrochemical Impedance Spectroscopy. Results and discussion Structure, microstructure, redox properties and oxygen vacancies are strictly correlated to the combustion fuel used. In particular, PEG seems to affect negatively the materials features, whereas the sample prepared by sucrose showed the best characteristics. Electrochemical results have been correlated with the materials properties. Conclusions The combustion fuel used during SCS strongly influences many physical-chemical properties which are relevant for the electrochemical performances of Ce and Co-doped Strontium Ferrites as cathodes for IT-SOFCs. Acknowledgments Authors are grateful to Dr. Giordano for XRD measurements and to PON-TESEO project for funding. References 1. Choi H., Fuller A., Davis J., Wielgus C., Ozkan U.S., Appl. Catal. B- Environ., 2012, 127, 336- 341. 2. Deganello F., Liotta L.F., Longo A., Casaletto M.P., Scopelliti M., J. Solid State Chem., 2006, 179(11), 3406 - 3419 3. Deganello F., Liotta L.F., Marcì G., Fabbri E., Traversa E., Mater Renew. Sustain. Energy, 2013, 2:8