Oxygen Permeation Measurements: An Alternative Tool to Select New Intermediate Temperature Solid Oxide Fuel Cell Cathodes

In this contribution four perovskite-based mixed ionic-electronic conductors (MIEC): a strontium and iron doped lanthanum gallate (La 0.8Sr0.2Ga0.8Fe0.2O3, hereafter LSGF8282), and strontium or cobalt doped lanthanum cuprates (La 0.7Sr0.3CuO3-LSC7310, La2Cu 0.8Co0.2O4-LCC2082 and LaCu 0.3Co0.7O3-LCC1037), were synthesized by means of a wet-chemistry routes (Pechini method) and characterized by X-Ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), specific surface area (by the BET single point method) and Scanning Electron Microscopy (SEM). The oxygen permeation properties were investigated by means of a home made permeation chamber at 600, 700 and 800 °C in order to evaluate their applicability as cathode materials in intermediate temperature solid oxide fuel cells (IT-SOFCs). The synthetic procedure allowed to achieve the desired compounds, as confirmed by XRD and XPS measurements. The A2BO 4-type sample (LCC2082) showed higher oxygen permeation rate than ABO3 perovskites. This is ascribed to the oxygen transportation extra contribution through the AO planes present in A2BO4 compound. Among the ABO3-type samples, the copper-rich ones showed the most interesting oxygen permeation.