Research output: Contribution to journal › Article › peer-review
Effect of isosymmetric phase transition in MIEC perovskite on the kinetic parameters of its interaction with oxygen. / Popov, Mikhail P.; Gongola, Marko I.; Kovalev, Ivan V. et al.
In: Chemical Engineering Journal, Vol. 475, 146082, 01.11.2023.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Effect of isosymmetric phase transition in MIEC perovskite on the kinetic parameters of its interaction with oxygen
AU - Popov, Mikhail P.
AU - Gongola, Marko I.
AU - Kovalev, Ivan V.
AU - Guskov, Rostislav D.
AU - Chizhik, Stanislav A.
AU - Nemudry, Alexander P.
N1 - The research was supported by RSF № 22-73-10200, https://rscf.ru/project/22-73-10200/.
PY - 2023/11/1
Y1 - 2023/11/1
N2 - Oxygen partial pressure relaxation technique was used to study transient kinetics of re-equilibration in the reaction of nonstoichiometric oxide Ba0.5Sr0.5Co0.75Fe0.2Mo0.05O3-δ with oxygen within a region of 3-δ stoichiometry close to the nominal oxidation state 3+ for cobalt where an isosymmetric phase transition cubic perovskite P1 – cubic perovskite P2 is observed. The relaxation data were analyzed using a macrokinetic model that explicitly takes into account the power-law dependence of the surface reaction rate on the oxygen partial pressure. A twofold decrease in the power-law exponent (n = 0.7 to n = 0.3) was found at the point of the P1-P2 phase transition, which indicates a change in the mechanism of the rate-determining step of the reaction caused by the transition. At the same time, the functional dependence of the diffusion mobility of oxygen vacancies on the equilibrium oxygen pressure does not change at the transition point, which means that the transition does not affect the mechanism of bulk vacancy mobility.
AB - Oxygen partial pressure relaxation technique was used to study transient kinetics of re-equilibration in the reaction of nonstoichiometric oxide Ba0.5Sr0.5Co0.75Fe0.2Mo0.05O3-δ with oxygen within a region of 3-δ stoichiometry close to the nominal oxidation state 3+ for cobalt where an isosymmetric phase transition cubic perovskite P1 – cubic perovskite P2 is observed. The relaxation data were analyzed using a macrokinetic model that explicitly takes into account the power-law dependence of the surface reaction rate on the oxygen partial pressure. A twofold decrease in the power-law exponent (n = 0.7 to n = 0.3) was found at the point of the P1-P2 phase transition, which indicates a change in the mechanism of the rate-determining step of the reaction caused by the transition. At the same time, the functional dependence of the diffusion mobility of oxygen vacancies on the equilibrium oxygen pressure does not change at the transition point, which means that the transition does not affect the mechanism of bulk vacancy mobility.
KW - MIEC oxides
KW - OPPR
KW - Oxygen exchange
KW - Phase Transition
KW - Relaxation kinetics
UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85171652447&origin=inward&txGid=35329c53cb8fc27b0b59086d2f072c24
UR - https://www.mendeley.com/catalogue/3bbbde5d-4f03-3ab2-95fd-14f3a611d580/
U2 - 10.1016/j.cej.2023.146082
DO - 10.1016/j.cej.2023.146082
M3 - Article
VL - 475
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
M1 - 146082
ER -
ID: 55507371