Pr-doped ceria nanoparticles as intermediate temperature ionic conductors

One of the most important challenges for further development of solid oxide fuel cells is to develop new electrolytes which operate at intermediate temperatures. In this sense, the Ce0.8Pr0.2O2 material has been synthesized for the first time using polyol-mediated synthesis route, obtaining well crystallized nanoparticles with a particle size of 2–3 nm. In order to study the thermomechanical properties of the sample, dilatometric measurements have been carried out. The Ce0.8Pr0.2O2 nanostructured sample exhibits a thermal expansion coefficient of 22.1 × 10−6 K−1, making this material one of the first electrolytes compatible with cobaltites and double perovskites, the most promising cathodes for these devices. The electrochemical behavior of these nanoparticles has been studied and the influence of the particle size on the material properties has been also analyzed. The nanostructured electrolyte presents bulk conductivity much higher than microstructured samples, giving rise to an improvement of the electrolyte performance. Experimental results indicate that Ce0.8Pr0.2O2 nanoparticles exhibit a lot of advantages for their employment as electrolyte material in terms of smaller particle size and better electrochemical performance.