CeO2-ZrO2-Sc2O3 nanomaterials with mixed ionic-electronic conductivity as SOFC anodes

L.M. TOSCANI; H. TROIANI; D.G. LAMAS; S.A. LARRONDO; L.V. MOGNI

Buenos Aires

Congreso; VIII Symposium on Hydrogen, Fuel Cells and Advanced Batteries - HYCELTEC 2022; 2022

Solid Oxide Fuel Cells (SOFCs) have been intensively studied in the past years due to its highly efficient energy conversion and its versatility toward clean fuel utilization. In this sense, the development of an economically feasible SOFC technology has driven the research activity in this area toward the reduction of their operating temperature to the intermediate temperature (IT) regime (500 °C -800 °C). New anode materials need to be developed with mixed ionicelectronicconductivity, high electrocatalytic activity and resistance to coke deposition when hydrocarbons are used as fuel.Nanostructured CeO2-ZrO2 (CeZr) exhibits excellent redox properties and electronic conductivity in reducing atmospheres due to the presence of the Ce4+/Ce3+ couple and high oxygen mobility in its lattice that enhances the materials resistance to carbon and/or sulfur formation from thefuel [1]. In order to improve oxygen mobility and redox capacity, aliovalent doping can help to introduce additional oxygen vacancies in the crystal lattice and is expected to improvethe materials resistance to carbon formation.In this work, we assess the effect of the addition of an aliovalent dopant (Sc3+) to the CeZr lattice in the generation of oxygen vacancies and its impact in the polarization resistance of CeZr and CeZrSc anodes when using diluted H2 and CH4 as fuels. The different electrode processes and rate-determining steps are analyzed as a function of temperature and variation of the fuel atmosphere.