Suchergebnisse

The current work focuses on the investigation of the structural and electrical properties of La2NiO4±δ, La1.7Sr0.3NiO4±δ and La1.7Ca0.3NiO4±δ layered perovskites and electrochemical performance of the cathodes on their base in contact with the Ce0.8Sm0.2O1.9 electrolyte with special attention given to the influence of the introduction of the sintering additives (CuO, Bi0.75Y0.25O1.5) into cathode layers on their in-plane and polarization resistances. Studies by the dc four-probe technique and impedance spectroscopy were performed on the samples with/without the collector layer on a base of LaNi0.6Fe0.4O3 with different sintering temperatures of the electrode layers. © 2014 The Authors. Published by Elsevier Ltd. ; This work has been partly done using facilities of the shared access center "Composition of compounds" IHTE, UB RAS, and supported by the Russian Foundation for Basic Research, the Government of Sverdlovsk region and Presidium of Ural Branch of RAS (projects №№13-03-96098, 14-03-00414, 14-08-31030, 12-S-3-1016).

The oxygen surface kinetics of Sr2Fe1.5Mo0.5O6−δ was determined using the 16O2/18O2 isotope exchange method with gas phase analysis at 600-800 °C. The heterogeneous exchange rates (rH) and the oxygen diffusion coefficients (D) were calculated by processing the concentration dependences of the 18O fraction using Ezin's model. The rates of oxygen dissociative adsorption (ra) and incorporation (ri) were calculated based on a model using the three exchange type rates. It has been established that the rates ra and ri were comparable in this temperature range. Assumptions were made about the effect of the chemical composition of the surface on the rate of oxygen adsorption. It was found that the oxygen exchange coefficient (k) of Sr2Fe1.5Mo0.5O6−δ is comparable to that of La0.6Sr0.4MnO3±δ oxide. High values of the oxygen diffusion coefficient were found for Sr2Fe1.5Mo0.5O6−δ. The values were comparable to those of the double cobaltite praseodymium-barium and exceed by more than an order those of lanthanum‐strontium manganite. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). ; Russian Foundation for Basic Research, RFBR: 00161 ; Government Council on Grants, Russian Federation ; The study was partly financially supported by the Russian Foundation for Basic Research (17-08-00161) and the Russian Federation Government, agreement 02.A03.21.0006 (no. 211).

In the field of modern hydrogen energy, obtaining pure hydrogen and syngas and then being able to use them for green energy production are significant problems. Developing solid oxide fuel cells (SOFC) and catalytic membranes for oxygen separation as well as materials for these devices is one of the most likely ways to solve these problems. In this work, the authors' recent studies in this field are reviewed; the fundamentals of developing materials for SOFC cathodes and oxygen separation membranes' permselective layers based on research of their oxygen mobility and surface reactivity are presented. Ruddlesden – Popper phases Ln2–xCaxNiO4+δ (LnCNO) and perovskite-fluorite nanocomposites PrNi0.5Co0.5O3–δ–Ce0.9Y0.1O2–δ (PNC–YDC) were studied by isotope exchange of oxygen with C18O2 and 18O2 in flow and closed reactors. For LnCNO a high oxygen mobility was shown (D* ~ 10–7 cm2/s at 700 °C), being provided by the cooperative mechanism of oxygen migration involving both regular and highly-mobile interstitial oxygen. For PNC–YDC dominated a wide fast diffusion channel via fluorite phase and interphases due to features of the redistribution of cations resulting in superior oxygen mobility (D* ~ 10–8 cm2/s at 700 °C). After optimization of composition and nanodomain structure of these materials, as cathodes of SOFC they provided a high power density, while for asymmetric supported oxygen separation membranes – a high oxygen permeability. © 2020 ; Support of different parts of the work by the Russian Science Foundation (Project 16-13-00112) and the budget project №AAAA-A17-117041110045-9 for Boreskov Institute of Catalysis is gratefully acknowledged. The authors from the Ural Federal University are grateful to the Government of the Russian Federation (Agreement 02.A03.21.0006, Act 211). Ce 0.9 Y 0.1 O 2–δ |Ce 0.9 Gd 0.1 O 2–δ |Ni/Zr 0.84 Y 0.16 O 2–δ anodic half-cells and Ni/Al foam substrates were kindly provided by H.C. Starck, Germany and Powder Metallurgy Institute NAN Belarus, respectively. Authors would like to appreciate International Conference on Advances in Energy Systems and Environmental Engineering (ASEE19, Wroclaw, Poland, June 9-12, 2019) Organization Committee.