Structural,Magnetic and Catalytic Properties of a New Vacancy Ordered Perovskite Type Barium Cobaltate BaCoO2.67 |
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| Authors: | Aamir Iqbal Waidha Humera Khatoon Siddiqui Dr Yuji Ikeda Dr Maren Lepple Dr Sami Vasala Manuel Donzelli Dr A D Fortes Dr Peter Slater Dr Blazej Grabowski Dr Ulrike I Kramm Dr Oliver Clemens |
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| Institution: | 1. Materials Synthesis Group, Institute of Material Science, University of Stuttgart, Hesisenbergstraße 3, 70569 Stuttgart, Germany;2. Catalysts and Electrocatalyst, Department of Chemistry, Eduard-Zintl Institute for Inorganic and Physical Chemistry, Technische Universität Darmstadt, 64287 Darmstadt, Germany;3. Department of Materials Design, Institute for Materials Science, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany;4. DECHEMA-Forschungsinstitut, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany;5. Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, ISIS Facility, Didcot, Oxfordshire, OX11 0QX UK;6. School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK |
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| Abstract: | A new vacancy ordered, anion deficient perovskite modification with composition of BaCoO2.67 (Ba3Co3O8□1) has been prepared via a two-step heating process. Combined Rietveld analysis of neutron and X-ray powder diffraction data shows a novel ordering of oxygen vacancies not known before for barium cobaltates. A combination of neutron powder diffraction, magnetic measurements, and density functional theory (DFT) studies confirms G-type antiferromagnetic ordering. From impedance measurements, the electronic conductivity of the order of 10?4 S cm?1 is determined. Remarkably, the bifunctional catalytic activity for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is found to be comparable to that of Ba0.5Sr0.5Co0.8Fe0.2O3–y, confirming that charge-ordered anion deficient non-cubic perovskites can be highly efficient catalysts. |
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| Keywords: | ab initio calculations bifunctional catalyst magnetism neutron diffraction perovskite |
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