Oxygen surface exchange and diffusion in Pr1.75Sr0.25Ni0.75Co0.25O4±: δ
Электронный научный архив УРФУ
Информация об архиве | Просмотр оригинала| Поле | Значение | |
| Заглавие |
Oxygen surface exchange and diffusion in Pr1.75Sr0.25Ni0.75Co0.25O4±: δ
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| Автор |
Tropin, E.
Ananyev, M. Porotnikova, N. Khodimchuk, A. Saher, S. Farlenkov, A. Kurumchin, E. Shepel, D. Antipov, E. Istomin, S. Bouwmeester, H. |
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| Тематика |
DIFFUSION
DISSOCIATION ISOTOPES KINETICS OXYGEN DISSOCIATIVE ADSORPTION EXPERIMENTAL CONDITIONS OXYGEN EXCHANGE KINETICS OXYGEN INCORPORATION OXYGEN ISOTOPE EXCHANGE OXYGEN SURFACE EXCHANGE STATISTICAL MODELING TWO-STEP MECHANISMS GAS ADSORPTION |
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| Описание |
Oxygen surface exchange and diffusion in Pr1.75Sr0.25Ni0.75Co0.25O4±δ have been investigated using two methods: pulsed isotope exchange (PIE) and oxygen isotope exchange with gas phase equilibration (IE GPE). Oxygen surface exchange kinetics is considered in the framework of two-step models including two consecutive stages: dissociative adsorption of oxygen and incorporation of oxygen adatoms into the crystal lattice. The rates of oxygen heterogeneous exchange (rH) as well as the rates of dissociative adsorption (ra) and oxygen incorporation (ri) have been calculated. The applicability of the two-step model is discussed based on the concept of a novel two-step mechanism with distributed rates of dissociative adsorption and incorporation of oxygen. It is shown that the two-step model can be applicable for the description of oxygen exchange kinetics in Pr1.75Sr0.25Ni0.75Co0.25O4±δ only at temperatures below 750 °C. Above this temperature, only the statistical model with distributed rates can be used. At low temperatures (<750 °C), the oxygen incorporation rate is found to be smaller than the rate of oxygen dissociative adsorption. Thus, under these experimental conditions the stage of oxygen incorporation is considered to be rate-determining. When increasing the temperature, the difference between ra and ri decreases and the stages become competing. The oxygen isotope exchange kinetic profiles obtained using the IE GPE method are found to be complicated and include a surface exchange stage as well as at least two diffusion relaxation processes. The reasons for the existence of these two processes are discussed. © 2019 the Owner Societies.
Government Council on Grants, Russian Federation The work was done using Unique scientific setup ‘‘Isotopic exchange’’ of the shared access center ‘‘Composition of Compounds’’ of IHTE UB RAS. The isotope exchange study is supported by the President Grant MS-6758.2018.3. The educational activities of Ph.D. involved into this work are supported by the Act 211 of the Government of the Russian Federation, Agreement No. 02.A03.21.0006. |
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| Дата |
2024-04-23T11:10:52Z
2024-04-23T11:10:52Z 2019 |
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| Тип |
Article
Journal article (info:eu-repo/semantics/article) Published version (info:eu-repo/semantics/publishedVersion) |
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| Идентификатор |
Tropin, E., Ananyev, M., Porotnikova, N., Khodimchuk, A., Saher, S., Farlenkov, A., … Bouwmeester, H. (2019). Oxygen surface exchange and diffusion in Pr1.75Sr0.25Ni0.75Co0.25O4±δ. Physical Chemistry Chemical Physics: PCCP, 21(9), 4779–4790. doi:10.1039/c9cp00172g
1463-9076 Final All Open Access, Green https://research.utwente.nl/files/166682803/c9cp00172g.pdf http://elar.urfu.ru/handle/10995/132548 10.1039/c9cp00172g 85062300753 000461722700005 |
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| Язык |
en
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| Права |
Open access (info:eu-repo/semantics/openAccess)
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| Формат |
application/pdf
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| Издатель |
Royal Society of Chemistry
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| Источник |
Physical Chemistry Chemical Physics
Physical Chemistry Chemical Physics |
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