Study of the isobaric and isostoichiometric kinetic parameters of oxygen exchange reaction of SrFe0.98Mo0.02O3-δ MIEC perovskite

The properties of perovskite related oxides ABO(3-delta) exhibiting mixed ionic-electronic conductivity (MIEC) are strongly dependent on oxygen stoichiometry 3-delta. The complexity of the theoretical interpretation of kinetic experiments is associated with the significant dependence of the kinetic properties of MIEC oxides on d. It is proposed to consider such grossly nonstoichiometric oxides having different oxygen stoichiometry as chemical homologues participating in the oxygen exchange reaction and forming a series continuous in delta. The continuous homologous series approach is considered using the example of SrFe(0.9)8Mo(0.02)O(3-delta). The equilibrium and kinetic properties of the oxide were studied by new methods of the oxygen partial pressure relaxation (OPPR) and quasi equilibrium oxygen release (QEOR). The power law dependence similar to p(n) of the kinetic parameters on the equilibrium oxygen partial pressure is considered as the consequence of linear free energy relationship similar to the Bronsted-Evans-Polanyi relation.

Automated summary

This study investigates the relationship between the properties of perovskite related oxides and the oxygen stoichiometry. It proposes a continuous homologous series approach and utilizes new methods to study the equilibrium and kinetic properties of SrFe(0.98)8Mo(0.02)O(3-delta). The power law dependence of the kinetic parameters on the equilibrium oxygen partial pressure is considered as a result of a linear free energy relationship.