Oxygen isotope exchange in La2NiO4±δ

2016 ◽  
Vol 18 (13) ◽  
pp. 9102-9111 ◽  
Author(s):  
M. V. Ananyev ◽  
E. S. Tropin ◽  
V. A. Eremin ◽  
A. S. Farlenkov ◽  
A. S. Smirnov ◽  
...  
Keyword(s):  
Gas Phase ◽  
Isotope Exchange ◽  
Exchange Method ◽  
Surface Exchange ◽  
Oxygen Isotope Exchange ◽  
Exchange Kinetics ◽  
And Diffusion ◽  
Oxygen Surface Exchange ◽  
Experimental Rig ◽  
Isotope Exchange Method

Oxygen surface exchange kinetics and diffusion have been studied by the isotope exchange method with gas phase equilibration using a static circulation experimental rig in the temperature range of 600–800 °C and oxygen pressure range of 0.13–2.5 kPa.

Oxygen surface exchange and diffusion in Pr1.75Sr0.25Ni0.75Co0.25O4±δ

2019 ◽  
Vol 21 (9) ◽  
pp. 4779-4790 ◽  
Author(s):  
Evgeniy Tropin ◽  
Maxim Ananyev ◽  
Natalia Porotnikova ◽  
Anna Khodimchuk ◽  
Saim Saher ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Gas Phase ◽  
Isotope Exchange ◽  
Surface Exchange ◽  
Oxygen Isotope Exchange ◽  
And Diffusion ◽  
Oxygen Surface Exchange ◽  
Oxygen Surface

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 and diffusion in mayenite single crystal

2019 ◽  
Vol 21 (44) ◽  
pp. 24740-24748 ◽  
Author(s):  
Anna S. Tolkacheva ◽  
Sergey N. Shkerin ◽  
Natalia M. Porotnikova ◽  
Mikhail V. Kuznetsov ◽  
Sergey V. Naumov ◽  
...  
Keyword(s):  
Single Crystal ◽  
Gas Phase ◽  
Surface Exchange ◽  
And Diffusion ◽  
Oxygen Surface Exchange ◽  
Oxygen Surface

Oxygen surface exchange and diffusion in Ca12Al14O33±δ single crystal were studied by a unique in situ method based on isotope equilibration in the gas phase.

Oxygen surface exchange kinetics of Ba0.5Sr0.5Co0.8Fe0.2O3−δ

2020 ◽  
Vol 22 (18) ◽  
pp. 10158-10169
Author(s):  
V. A. Eremin ◽  
M. V. Ananyev ◽  
H. J. M. Bouwmeester ◽  
E. Kh. Kurumchin ◽  
Ch.-Y. Yoo
Keyword(s):  
Gas Phase ◽  
Oxygen Exchange ◽  
Oxide Surface ◽  
Surface Exchange ◽  
Exchange Kinetics ◽  
Kinetics Of ◽  
Oxygen Surface Exchange ◽  
Oxygen Surface

The mechanism of oxygen exchange between the gas phase and Ba0.5Sr0.5Co0.8Fe0.2O3−δ oxide was evaluated by considering the inhomogeneity of the oxide surface.

Oxygen Isotope Exchange in Proton-Conducting Oxides Based on Lanthanum Scandates

2018 ◽  
pp. 70-87
Author(s):  
A. S. Farlenkov ◽  
A. V. Khodimchuk ◽  
N. A. Shevyrev ◽  
A. Yu. Stroeva ◽  
A. V. Fetisov ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Diffusion Coefficients ◽  
Isotope Exchange ◽  
Dissociative Adsorption ◽  
Surface Exchange ◽  
Oxygen Isotope Exchange ◽  
Conducting Oxides ◽  
Reducing Atmosphere ◽  
Oxygen Surface Exchange ◽  
Oxygen Surface

The method of oxygen isotope exchange with the gas phase equilibration have been used to obtain the temperature dependences of the oxygen surface exchange and diffusion coefficients with proton-conducting oxides La1–xSrxScO3–δ (x = 0; 0.04; 0.09) in the temperature range of 600−900°C at oxygen pressure 1.01 kPa. The paper determines that the diffusion and oxygen surface exchange coefficients increase with the increasing of the strontium content in the oxides. We have found out the rates of the individual stages of the oxygen exchange process on the surface of the oxides. It is shown that oxygen incorporation is rate-determining stage of the oxygen exchange on the surface of the undoped oxide, whereas for the strontium-doped oxides La1–xSrxScO3–δ (x = 0; 0.04; 0.09) with increasing of strontium concentration, the difference between the rates of dissociative adsorption and oxygen incorporation decreases so that for the oxide La0,91Sr0,09ScO3–δ the stage of dissociative adsorption of oxygen becomes rate-determining stage. The paper analyzes the possible reasons of these differences in oxygen surface exchange kinetics. Moreover, the paper using the obtained oxygen diffusion coefficients that have been recalculated in the oxygen-ionic conductivities according to the Nernst-Einstein equation performs the contributions of the oxygen-ion and proton components of the total conductivity of oxides La1–xSrxScO3–δ (x = 0; 0.04; 0.09) in the wet reducing atmosphere (pH2O = 2.35 kPa, pO2 = 10−15 Pa). Proton transference numbers are shown to be close to unit in the temperature range of 500–600 °С at the wet hydrogen-containing reducing atmosphere.

The Oxygen Mobility and Catalytic Activity of LaMO3±δ (M=Cr, Mn, Co) Phases

1999 ◽  
Vol 602 ◽  
Author(s):  
I.A. Koudriashov ◽  
L.V. Borovskikh ◽  
G.N. Mazo ◽  
S. Scheurell ◽  
E. Kemnitz
Keyword(s):  
Gas Phase ◽  
Oxygen Diffusion ◽  
Isotope Exchange ◽  
Oxidation Reaction ◽  
Freeze Drying ◽  
Exchange Method ◽  
Type Complex ◽  
Different Types ◽  
Perovskite Type ◽  
Isotope Exchange Method

AbstractThe activity of LaMO3, where M=Cr, Mn, Co, perovskite-type complex oxides in oxygen diffusion and catalytic processes was investigated. For sample preparation freeze-drying technique was used and dynamic thermal isotope exchange method was used to study exchange reaction between 18O from the gas phase and 16O from the samples synthesized, and to investigate the methane catalytic oxidation reaction. The results obtained allowed to indicate temperature intervals of different types of reaction taking place and that LaCrO3 is far less active in mentioned reactions than LaCoO3 and LaMnO3.

scholarly journals Influence of Heterointerfaces on the Kinetics of Oxygen Surface Exchange on Epitaxial La1.85Sr0.15CuO4 Thin Films

2021 ◽  
Vol 11 (9) ◽  
pp. 3778
Author(s):  
Gene Yang ◽  
So-Yeun Kim ◽  
Changhee Sohn ◽  
Jong K. Keum ◽  
Dongkyu Lee
Keyword(s):  
Thin Films ◽  
Oxygen Vacancies ◽  
Elevated Temperatures ◽  
Surface Exchange ◽  
Electrical Conductivity Relaxation ◽  
Exchange Kinetics ◽  
Relaxation Curves ◽  
Kinetics Of ◽  
Oxygen Surface Exchange ◽  
Oxygen Surface

Considerable attention has been directed to understanding the influence of heterointerfaces between Ruddlesden–Popper (RP) phases and ABO3 perovskites on the kinetics of oxygen electrocatalysis at elevated temperatures. Here, we report the effect of heterointerfaces on the oxygen surface exchange kinetics by employing heteroepitaxial oxide thin films formed by decorating LaNiO3 (LNO) on La1.85Sr0.15CuO4 (LSCO) thin films. Regardless of LNO decoration, tensile in-plane strain on LSCO films does not change. The oxygen surface exchange coefficients (kchem) of LSCO films extracted from electrical conductivity relaxation curves significantly increase with partial decorations of LNO, whereas full LNO coverage leads to the reduction in the kchem of LSCO films. The activation energy for oxygen exchange in LSCO films significantly decreases with partial LNO decorations in contrast with the full coverage of LNO. Optical spectroscopy reveals the increased oxygen vacancies in the partially covered LSCO films relative to the undecorated LSCO film. We attribute the enhanced oxygen surface exchange kinetics of LSCO to the increased oxygen vacancies by creating the heterointerface between LSCO and LNO.

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