Conference Presentation (After Call)

FZJ-2021-04007

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Y and Mn substituted BaZrO3 ceramics: material properties as a function of the substituents concentration

Ivanova, M. (Corresponding author)FZJ* ; Balaguer, M. ; Jalarvo, N. ; Fantin, A. ; Menzler, N. H.FZJ* ; Guillon, O.FZJ*

2021

Abstract: Innovations in material science are the key element for solving technological challenges. Various energy and environmental applications require designing materials with tailored compositions, microstructures and specific target-oriented performance. Y and Mn co-substituted BaZrO3, e.g. BaZr0.85Y0.15Mn0.05O3-δ (BZYM5), has previously attracted attention as a membrane material for H2 separation from gas mixture due to its mixed proton-electron conductivity leading to appreciable levels of H2-flux at elevated temperatures and its good thermo-chemical stability under reducing environments. In the present work, we developed ceramic materials within the BaZr0.8Y0.2-xMnxO3-δ series, where x =0.02, 0.05, 0.10, and systematically studied their functional properties in dependence of the Y-to-Mn ratio, including thermal behaviour, hydration and electrical properties. In addition to that, near edge X-ray absorption fine structure spectra (NEXAFS) in the vicinity of O K-edge and Mn L2,3-edges was carried out for selected BZYM specimens to collect information on oxidation states and surrounding symmetry of Mn atoms in surface- and bulk- sensitive modes. Finally, we studied proton diffusion in hydrated BZYM samples using quasi-elastic neutron scattering (QENS). Two distinct dynamic processes were observed at temperatures above 300 °C: one faster more localized process and another slower long-range diffusion process. The long-range diffusion has clear characteristics of jump-diffusion. We will present a model for atomic scale proton diffusion in these materials, and we will further discuss how Mn doping influences the proton diffusion in these materials.

Keyword(s): Energy (1st) ; Materials Science (2nd)

Note: Key words: mixed proton-electronic ceramic conductors, proton conducting ceramic cells, ceramic membranes for H2 separation, B-side double substituted BaZrO3, A(II)B(IV)O3 perovskites, BaZr0.8Y0.2-xMnxO3-δ, NEXAFS, QENS

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Contributing Institute(s):

1. Werkstoffsynthese und Herstellungsverfahren (IEK-1)

Research Program(s):

1. 1213 - Cell Design and Development (POF4-121) (POF4-121)
2. Verbundvorhaben ProtOMem: Entwicklung von protonenleitenden Membranen mit optimierter Mikrostruktur und verbesserten Transporteigenschaften für Energie- und Wasserstoffseparationsanwendungen (03SF0537A) (03SF0537A)

Appears in the scientific report 2021

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