Abstract
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.
Highlights
Production of syngas and pure hydrogen is a key problem in the field of modern hydrogen energy
One branch linked to these problems relates to the design of solid oxide fuels cells (SOFC) and catalytic membrane re actors in general and materials for SOFC cathodes and oxygen separation membranes, or their permselective layers, in particular
The key characteristics of the materials that affect the performance of these devices are related to oxygen mobility and surface reactivity [4,5,6,7,8,9]
Summary
Production of syngas and pure hydrogen is a key problem in the field of modern hydrogen energy. Pr nickelatescobaltites (PNC) are promising materials for SOFC cathodes and perm selective layers of oxygen separation membranes due to their compati bility with electrolytes (such as doped ceria), their stability to carbonization and their superior oxygen transport characteristics (oxy gen tracer diffusion coefficient (D*) value is up to ~ 10–8 cm2/s at 700 ◦C) [4,5,6,12,13,14,15] Another likely class of materials for these applications are Rud dlesden – Popper phases (RP) with regard to their moderate thermal expansion coefficients and a high mixed ionic-electronic conductivity [1,2,3,5,6,7,10,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34]. The membranes were tested in methane selective oxidation into syngas and oxi-dry reforming using a purpose-built kinetic setup [5,14,41,42] and an oven-placed doubleflange reactor assembly
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
