Effect of Ce‐Doping on the Electrical and Electrocatalytical Behavior of La/Sr Chromo‐Manganite Perovskite as New SOFC Anode

Abstract

AbstractThe effect of cerium substitution on the electrical and electrochemical characteristics of a new anode material La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) was examined by synthesizing CexLa0.75–xSr0.25Cr0.5Mn0.5O3 for x = 0–0.375). From x = 0–0.25, the structure is rhombohedral (S.G. R‐3c), and with a higher cerium content (x = 0.375) it becomes cubic (S.G. Pm‐3m). These materials are stable in the operating conditions of an SOFC anode. CexLa0.75–xSr0.25Cr0.5Mn0.5O3 and LSCM materials are p‐type semi‐conductors. Cerium substitution improves the conductivity in neutral atmosphere from 18.3 to 35.4 S cm–1 for x = 0 and 0.375, respectively, at 1,173 K. In reducing conditions, the conductivity is not influenced by cerium substitution, and it is about 1 S cm–1 at 1,173 K. High temperature XRD shows that structure becomes cubic at 1,073 K in operating (reducing) conditions. Cerium substitution positively enhances the electrochemical behavior, as proved by studying the properties of dense cone‐shaped electrodes.