Development of Zirconia-Based Mesoporous Materials for Intermediate-Temperature Solid-Oxide Fuel Cells

Abstract

Scandia-stabilized zirconia (Sc-ZrO2) is a popular choice for solid oxide fuel cells due to its high ionic conductivity at intermediate temperatures. Mesoporous 9 mol% Sc-ZrO2 powders for use in intermediate-temperature solid oxide fuel cells have been synthesized using sol-gel synthesis with zirconium ethoxide and scandium acetate in ethylene glycol as precursors and CTAB as the surfactant in the preparation of the powders. The preparation of mesoporous materials makes use of the self-assembling properties of surfactants while grain growth during calcination is slowed by the surfactant templating. The powders were calcined in air at 450°C for times ranging from 6 hours to 24 hours. The powders were characterized via XRD, DLS, SEM and TEM. In the as-synthesized state, x-ray diffraction patterns reveal that the powders are amorphous and are shown to be highly agglomerated through SEM and DLS. Upon calcination, some of the powders develop a porous structure and take on the cubic phase. Powders calcined for 12 hours at 450°C show the best porosity: pore diameter between 100 and 200 nanometers. The DLS results show that the powders are agglomerated to an average of approximately 325 nm. Utilization of a surfactant as the template promotes the formation of pores while slowing grain growth.All files are JPEG or TIFF format.