Facile synthesis of doped ceria‐based oxide by co‐precipitation technique and performance evaluation in solid oxide fuel cell
Shoroshi Dey, Debasmita Choudhury, Mayuri Choudhuri, Abir Bhattacharya, Jayanta Mukhopadhyay, Abhijit Das Sharma, Madhumita Mukhopadhyay
Abstract
Abstract Co‐precipitated nanocrystalline gadolinium (Gd)‐doped ceria (CeO 2 ) has been synthesized with varying mole ratios of Gd in CeO 2 from 0.1‐0.8 with intricate maintenance of solution pH. Phase pure Gd‐doped CeO 2 (CGO) is obtained after calcination at 750°C and depending on the mole % dopant concentration, the typical crystallite size is found to vary in the range 9‐27 nm. Careful observation reveals that, calcined particle size decreases with the decrease in Gd content and an optimization of the particle size with exposed (111) [stable] and (100) plane [reactive] happens to occur for Ce 0.8 Gd 0.2 O 2− δ (CG 0.8 ). High resolution transmission electron micrograph of CG 0.8 reveals highly interpenetrating lattice planes corresponding to cubic fluorite structure. The effectivity of such CG 0.8 is further supported by its high electrical conductivity of 0.02 and 0.105 S/cm @ 600 and 700°C respectively. The bulk impedances exhibit ohmic ( R 0 ) and interfacial ( R p ) polarizations to be 146 and 29.96 Ω cm 2 at a temperature of 600 and 700°C with activation energies 0.36 and 0.8 eV respectively. The application of CG 0.8 is further established as an interlayer in nickel oxide‐yittria stabilized zirconia (NiO‐YSZ)/YSZ/CGO/La‐Sr‐Co‐Fe‐based single cell with a current density of 1.2 A/cm 2 @ 0.5 V and 700°C using hydrogen as the fuel and oxygen as the oxidant.