Preparation and characterization of Ca–Sm–Ce mixed oxides via cellulose templating method for solid oxide fuel cell applications

Abstract

SmxCa0.2−xCe0.8Oy materials are synthesized by changing mol ratios of the composition as x = 0, 0.05, 0.1, 0.15 and 0.2, respectively, with a fast and facile cellulose templating method for the first time. Microstructures of the calcined and sintered samples are characterized by XRD and SEM-EDX. Density measurements are actualized by using Archimedes method. The electrical conductivity of the samples is obtained from two-probe impedance spectroscopy. Maximum solubility limit of CaO in CeO2 is found to be 9.4 mol% from the XRD results. Incorporation of CaO slightly increases the sinterability of the samples. It is observed that Sm+3 expands the CeO2 lattice more than Ca+2. 10 mol% CaO incorporated sample show the highest total conductivity with the value of 0.032 S cm−1 at 800 °C. Obtained results show that Sm0.1Ca0.1Ce0.8Oy can be an excellent candidate for intermediate temperature solid oxide fuel cell applications due to its lower cost and higher performance compared to Sm0.2Ce0.8Oy at 800 °C. Additionally, cellulose templating method can be used as an effective method in order to prepare mixed oxide structures since the performances of the samples are higher than the samples which are prepared by more complex or costly hydrothermal and co-precipitation methods in literature.