Synthesis and electrochemical behaviour of ceria-substitution LSCM as a possible symmetric solid oxide fuel cell electrode material exposed to H2 fuel containing H2S

Abstract

12.5 wt.% ceria-substituted on the A-sites of La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCM) for La0.75Sr0.125 Ce0.125Cr0.5Mn0.5O3−δ (LSCCM) has been synthesized by the sol–gel process and evaluated as the electrode materials of symmetric solid oxide cells. The orthorhombic perovskite-type structure was demonstrated using X-ray diffraction (XRD) and part of cerium has been successfully doped to LSCM and presents two valence states (+3 and +4). In addition, the surface adsorption oxygen content increases due to ceria-doping using X-ray photoelectron spectroscopy (XPS). The measured electrical conductivity shows that the addition of ceria yields increase in total conductivity in air and humidified H2. Electrochemical performance test of yttria-stabilized zirconia (YSZ) electrolyte-supported symmetric solid oxide fuel cell with the configuration of LSCCM|YSZ|LSCCM was performed, and shows peak power density of 33.12 mW cm−2 at 1173 K when operating in wet 3% H2–1% H2S, far greater than the one of LSCM in the same test conditions.