Development of sulfur-tolerant fuel electrode of solid oxide electrolyser cell

• Main Author: Teo, Shawn Thian Shun
• Other Authors: Chan Siew Hwa
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Mechanical engineering::Energy conservation
• Online Access: http://hdl.handle.net/10356/60342
• Institution: Nanyang Technological University

In this project, the main aim is the development of sulfur-tolerant fuel electrode of solid oxide electrolyser cell (SOEC) through carbon dioxide electrolysis testing. Two different electrodes will be used for this project: the pure nickel-yttria-stabilised zirconia (Ni-YSZ) electrode that is commonly being used and a nickel-yttria-stabilised zirconia electrode impregnated with lanthanum chromo-manganite La0.75Sr0.25Cr0.5Mn0.5O3 – δ (LSCM). Standard testing of potential-current density relationships and impedance spectroscopy will be done to determine the electrochemical performance of the electrodes. For the electrolysis of carbon dioxide, potential-current density and impedance spectroscopy readings were taken at different concentrations of carbon dioxide, and at varying temperatures to observe and study the different effects of varying conditions on the electrochemical performance of both the pure and impregnated electrode. Following that, sulfur tolerance of the electrodes was examined. The electrodes were treated with different concentrations of sulfur dioxide in a hydrogen/nitrogen stream and the potential-current density and impedance spectroscopy curves were again recorded at varying concentrations of carbon dioxide to look at the electrochemical performance of both electrodes and to determine whether the modified electrode was more tolerant to sulfur contaminant than the original electrode. The obtained results indicate that the lanthanum chromo-manganite impregnated nickel-yttria-stabilised zirconia electrode is more promising in terms of sulfur-tolerance as compared to the pure nickel-yttria-stabilised zirconia electrode. The study of cell microstructure using the scanning electron microscope was also done to look at the different microstructures of the two electrodes, providing further reasons for the better sulfur tolerance of the lanthanum chromo-manganite impregnated electrode.