Oxygen Mobility and Surface Reactivity of Ca-Doped Pr2NiO4 - Доклады на конференциях | Sciact - CRIS-система Института катализа

Oxygen Mobility and Surface Reactivity of Ca-Doped Pr2NiO4 Доклады на конференциях

Язык

Английский

Тип доклада

Устный

Конференция

21 International Conference on Solid State Ionics
18-23 июн. 2017 , Padua

Авторы

Sadykov Vladislav ^1,2 , Pikalova Elena ^3,4 , Kolchugin Alexander ^3,4 , Eremeev Nikita ¹ , Bogdanovich Nina ³ , Skriabin Pavel ¹ , Krasnov Aleksey ¹ , Sadovskaya Ekaterina ^1,2 , Shmakov Alexander ^1,2,3 , Vinokurov Zakhar ^1,5 , Ishchenko Arcady ^1,2 , Pikalov Sergey ^4,6 , Fionova Elena ⁴

Организации

1	Институт катализа им. Г.К. Борескова СО РАН
2	Новосибирский национальный исследовательский государственный университет
3	Институт высокотемпературной электрохимии УрО РАН
4	Уральский федеральный университет имени первого Президента России Б.Н. Ельцина
5	Институт ядерной физики имени Г.И. Будкера СО РАН
6	Институт металлургии Уральского отделения Российской академии наук

Materials with a high mixed ionic-electronic conductivity are required for design of oxygen separation membranes and cathodes of solid oxide fuel cells. Ln2NiO4 oxides with Ruddlesden–Popper (R P) structure are promising materials due to their high oxygen mobility [1]. This work presents results of studies of structural and transport properties of Ca-doped Pr2NiO4. Pr2 xCaxNiO4 oxides (x=0 0.6) were synthesized by the co-precipitation method and characterized by XRD and TEM. The oxygen mobility for powdered samples was studied by the temperature-programmed oxygen isotope heteroexchange with C18O2 (TPIE) and unit cell volume relaxation after changing pO2. Up to x=0.5, samples were single-phase R P oxides, while at x=0.6 NiO admixture appears. At increasing x the space group varies in the row Fmmm→I4/mmm→Bbcm with the unit cell volume slightly decreasing. Doping results in enhancement of thermodynamic stability and electrical conductivity, while oxygen mobility decreases. This is explained by decreasing the oxygen excess and hampering cooperative mechanism of diffusion via oxygen migration between interstitial and regular positions [1]. For x>0.3 increasing the lattice anisotropy results in co-existing of 2-3 channels of oxygen diffusion revealed by separate peaks in TPIE curves [2]. A fast diffusion channel (DO~10 8 cm2/s at 700 °C, minor route) corresponds to cooperative mechanism, while slow ones (DO<10 10 cm2/s, main routes) are related to transport in perovskite layers and via interlayer positions near the dopant cation sites. Oxygen mobility and surface reactivity characteristics under the gradient of chemical potential are close to those for previously studied R P oxides [1]. Acknowledgements Support by Russian Science Foundation (Project 16-13-00112), Government of the Russian Federation (Agreement 02.A03.21.0006, Act 211) and shared-access centers “Composition of compounds” and “Ural-M” is gratefully acknowledged. References [1] V. Sadykov et al. Solid State Ionics 262 (2014) 918 922. [2] V. Sadykov et al. Solid State Ionics 288 (2016) 76–81.

Sadykov V. , Pikalova E. , Kolchugin A. , Eremeev N. , Bogdanovich N. , Skriabin P. , Krasnov A. , Sadovskaya E. , Shmakov A. , Vinokurov Z. , Ishchenko A. , Pikalov S. , Fionova E.
Oxygen Mobility and Surface Reactivity of Ca-Doped Pr2NiO4
21 International Conference on Solid State Ionics 18-23 Jun 2017