Synthesis of Mo-doped CeO₂by the Combustion Method for Carbon-Air Fuel Cells Applications: Study of Composition, Crystalline Structure and Mechanical Properties

Abstract

Molybdenum-doped ceria (CMO) is a promising material for the fabrication of anodes for carbon-air fuel cells. In this work, Ce 0.9 Mo 0.1 O 2+δ was synthesized by the combustion method, which reports lower synthesis times than the solid-state reaction and Pechini methods. The material obtained does not present impurities (determined by EDS analysis) and forms Fm-3m (225 space group) single phase fluorite-type structures with a cell parameter of ca. 5.419 Å (determined by Rietveld refinement). The mechanical properties of this material were studied using dense pellets produced by pressing the powders (pressure of ca. 105 MPa) and sintering the tablets obtained at 1000°C for 24 hours. The Young's modulus (291.7 GPa) and Vickers microhardness (between 4694 and 2474.4 MPa) were determined by using the resonant frequency method and Struers microhardness tester, respectively. Future work considers the complete characterization of mechanical and electrical properties of CMO with different amounts of dopant.