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

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 400 h using He as the sweep gas. The oxygen fluxes are 0.40, 0.34 and 0.29 ml/(cm2 min) 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 428 h at 950 °C. The CH4 conversion of 94% and the CO selectivity of 95% with the oxygen flux of 5.6 ml/(cm2 min) 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.