Abstract
A new vacancy ordered, anion deficient perovskite modification with composition of BaCoO(2.67) (Ba(3) Co(3) O(8) □(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 Ba(0.5) Sr(0.5) Co(0.8) Fe(0.2) O(3-y) , confirming that charge-ordered anion deficient non-cubic perovskites can be highly efficient catalysts.