Oxygen permeability and structure stability of a novel cobalt-free perovskite Gd0.33Ba0.67FeO3−δ

Abstract

A novel cobalt-free perovskite oxide based on Gd0.33Ba0.67FeO3−δ (GBF) was successfully prepared through a complexing method. X-ray diffraction (XRD) results reveal that the GBF possesses good structure and phase reversibility under low oxygen partial pressures and reducing atmosphere. The GBF membrane was steadily operated for 400h using He as the sweep gas. The oxygen fluxes are 0.40, 0.34 and 0.29ml/(cm2min) for the membrane at 975, 950 and 925°C, respectively. The reactor constructing by the GBF membrane was used for the partial oxidation of methane (POM) to syngas. The GBF membrane reactor for the POM was successfully operated for 428h at 950°C. The CH4 conversion of 94% and the CO selectivity of 95% with the oxygen flux of 5.6ml/(cm2min) are obtained. XRD, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) characterizations indicate that the GBF membrane exhibits good phase structure stability for the membrane even after long-term operation under syngas production conditions.