TY - JOUR

T1 - Equilibrium and kinetic parameters of oxygen exchange in mixed ionic electronic conducting perovskite-related oxide La2NiO4+δ

AU - Fouad, Mario

AU - Tropin, Evgeniy

AU - Guskov, Rostislav

AU - Kovalev, Ivan

AU - Gongola, Marko

AU - Popov, Mikhail

AU - Nemudry, Alexander

N1 - This work was supported by the state assignment to ISSCM SB RAS, project No. 121032500059-4.

PY - 2025/2/21

Y1 - 2025/2/21

N2 - Mixed ionic electronic conductors (MIEC) are increasingly recognized as essential materials for electrodes in solid oxide cell (SOC) applications, primarily due to their advantageous properties, which include high electronic conductivity, significant oxygen diffusivity, and favorable surface exchange coefficients. Among these materials, the oxygen-excess lanthanum nickelate La2NiO4+δ (LNO) has emerged as a particularly promising candidate for cathode applications in solid oxide fuel cells (SOFCs). In this study, we investigated the equilibrium properties of LNO by constructing the isothermal equilibrium diagram, represented as “lg pO2 – 4+δ – T″ using quasi-equilibrium oxygen release techniques. In addition, we have used oxygen partial pressure relaxation methods to study the kinetic properties of LNO to derive key parameters such as the equilibrium oxygen exchange rate (R0), the chemical diffusion coefficient within the oxide (Dchem), and the surface exchange rate constant (kchem). Our results show a remarkable Brønsted-Evans-Polanyi-type linear free energy relationship between the activation energy of the reaction rate constant and the standard change in Gibbs free energy associated with the reaction. This relationship highlights the complicated thermodynamic relationships that determine the behavior of LNO during oxygen exchange processes.

AB - Mixed ionic electronic conductors (MIEC) are increasingly recognized as essential materials for electrodes in solid oxide cell (SOC) applications, primarily due to their advantageous properties, which include high electronic conductivity, significant oxygen diffusivity, and favorable surface exchange coefficients. Among these materials, the oxygen-excess lanthanum nickelate La2NiO4+δ (LNO) has emerged as a particularly promising candidate for cathode applications in solid oxide fuel cells (SOFCs). In this study, we investigated the equilibrium properties of LNO by constructing the isothermal equilibrium diagram, represented as “lg pO2 – 4+δ – T″ using quasi-equilibrium oxygen release techniques. In addition, we have used oxygen partial pressure relaxation methods to study the kinetic properties of LNO to derive key parameters such as the equilibrium oxygen exchange rate (R0), the chemical diffusion coefficient within the oxide (Dchem), and the surface exchange rate constant (kchem). Our results show a remarkable Brønsted-Evans-Polanyi-type linear free energy relationship between the activation energy of the reaction rate constant and the standard change in Gibbs free energy associated with the reaction. This relationship highlights the complicated thermodynamic relationships that determine the behavior of LNO during oxygen exchange processes.

KW - Lanthanum nickelate oxide

KW - Layered perovskites

KW - Oxygen partial pressure relaxation

KW - Quasi equilibrium oxygen release

UR - https://www.mendeley.com/catalogue/789c19ac-4ee6-3231-84ac-5914589d5e93/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85219578446&origin=inward&txGid=6b720331943da8f3eb3cd03ebd6d74f8

U2 - 10.1016/j.ceramint.2025.02.313

DO - 10.1016/j.ceramint.2025.02.313

M3 - Article

JO - Ceramics International

JF - Ceramics International

SN - 0272-8842

ER -