| Synthesis and characterization of Pr2NiO4+δ via a combustion sol-gel method with citric acid as fuel for IT-SOFC cathode |
| Paper ID : 1346-UFGNSM-FULL |
| Authors: |
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Mina Naeini1, Mohammad Ali Faghihi Sani *2 1department of materials science and engineering, Sharif university of technology, Tehran, Iran 2Department of materials sciencd and engineering, Sharif university of technology, Tehran, Iran |
| Abstract: |
| Solid oxide fuel cells as high temperature electrochemical devices draw much attention in the last decades due to their fuel flexibility, high efficiency and low pollution. However, lowering operating temperature from 800-1000°C to 500-700°C has remained a challenge. To overcome this problem, mixed ionic and electronic conducting ceramics (MIECs) which exhibit less polarization resistance due to the extended electrochemical reaction zone, can be used as cathode materials in intermediate-temperature solid oxide fuel cells (IT-SOFCs). Amongst MIECs, the first member of Ruddlesden–Popper phases formulated Ln2NiO4+δ (Ln= La,Nd,Pr) in which one LnO3 perovskite is stuck between two LnO rock-salt layers, are of great interest because of their ability to embed extra oxygen in lattice without doping. In the present study, Pr2NiO4+δ powders with different over-stoichiometry values were synthesized via a combustion sol-gel method similar to that outlined by Pechini. The influence of citric acid content (as the fuel) on non-stoichoimetry level and microstructure of the synthesized powders was studied. X-ray diffraction and scanning electron microscopy on the samples showed that ultrafine crystallites of pure Pr2NiO4+δ were obtained via aforementioned method. Iodometric titration which was manipulated to evaluate δ, indicated that higher δ values correspond to higher citric acid contents. As non-stoichiometry level affects both ionic and electronic conductivities, our process seems to be suitable to prepare cathodes with different electrochemical performances. |
| Keywords: |
| IT-SOFC, Cathode, Pr2NiO4+δ, Combustion Sol-Gel, Over-stoichiometry, citrate/nitrate ratio. |
| Status : Paper Accepted (Oral Presentation) |
