Strong Co-Mo Interaction behind Unexpected Physicochemical Properties in SrMo0.9Co0.1O3-δPerovskite

LEANDRO M. ACUÑA; MARCELO D. CABEZAS; RODOLFO O. FUENTES; FERNANDO F. MUÑOZ

Journal of Physical Chemistry C

American Chemical Society

Año: 2021 vol. 125 p. 17342 - 17354

A novel combined chemical procedure was employed to synthesize ahomogeneous SrMo0.9Co0.1O3−δ (SMC) perovskite at lower temperatures (900 °C).The physicochemical properties of SMC were analyzed by means of in situ X-raydiffraction and X-ray absorption spectroscopy experiments under reducing andoxidizing conditions from 20 to 700 °C. The study revealed a strong interactionbetween Mo and Co cations in the SMC perovskite, which led to their unexpectedoxidation number speciation and a critical modification of their first coordination shell.Perovskite-like unit cells containing Co in their center can drastically increase theoccupation number of oxygen anions, enhancing SMC oxygen storage capability.Under reducing conditions, these loosely bonded anions were easily released from thematerial to chemically react with H2 in the gas phase. These findings bring novelinsights into the physicochemical processes that take place in SMC materials and giverise to the catalytic and electrochemical activity that makes this material a candidate forintermediate temperature-SOFC anode application.