Oxygen Reduction Mechanisms in Nanostructured La0.8Sr0.2MnO3 Cathodes for Solid Oxide Fuel Cells

MEJÍA GÓMEZ, AUGUSTO; FERRARI, VALERIA; LAMAS, DIEGO G.; MARTINELLI, HERNÁN; JUAN, DILSON; PRUNEDA, MIGUEL; SACANELL, JOAQUÍN; LEYVA, ANA G.; SIEPE, JIMENA; PRUNEDA, MIGUEL; HERNÁNDEZ SÁNCHEZ, JOAQUÍN; RUBIO LÓPEZ, ADRIÁN EZEQUIEL; LEYVA, ANA G.; MEJÍA GÓMEZ, AUGUSTO; LAMAS, DIEGO G.; RUBIO LÓPEZ, ADRIÁN EZEQUIEL; FERRARI, VALERIA; JUAN, DILSON; MARTINELLI, HERNÁN; SIEPE, JIMENA; SACANELL, JOAQUÍN; HERNÁNDEZ SÁNCHEZ, JOAQUÍN

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington D.C; Año: 2017 vol. 121 p. 6533 - 6539

1932-7447

In this work we outline the mechanisms contributing to the oxygen reduction reaction in nanostructured cathodes of La0.8Sr0.2MnO3 (LSM) for Solid Oxide Fuel Cells (SOFC). These cathodes, developed from LSM nanostructured tubes, can be used at lower temperatures compared to microstructured ones, and this is a crucial fact to avoid the degradation of the fuel cell components. This reduction of the operating temperatures stems mainly from two factors: (i) the appearance of significant oxide ion diffusion through the cathode material in which the nanostructure plays a key role and (ii) an optimized gas phase diffusion of oxygen through the porous structure of the cathode, which becomes negligible. A detailed analysis of our Electrochemical Impedance Spectroscopy supported by first-principles calculations point toward an improved overall cathodic performance driven by a fast transport of oxide ions through the cathode surface. (Figure Presented).