Kim, Hayoung Lee, Jaehyuck Gokbayrak, Attila Alkim Seo, Yebon Oh, Seongkook Oh, Min Jun Jun, Yongseok Son, Ji-Won Yang, Sungeun 2024-06-13T01:30:41Z 2024-06-13T01:30:41Z 2024-06-13 2024-05 0360-3199 https://pubs.kist.re.kr/handle/201004/150056 Ammonia can be directly utilized in solid oxide fuel cells, known as direct-ammonia solid oxide fuel cells (DASOFCs), which are among the most efficient technologies for ammonia utilization. Current research efforts are directed towards lowering the operating temperatures of DA-SOFCs by incorporating additional catalysts. However, critical analyses regarding the extent of ammonia decomposition on metallic interconnects and Ni current collectors, as well as the negative effect of residual ammonia on performance, are lacking. In this study, we examine DA-SOFCs with a single-repeating unit stack on a small scale, addressing the effects of metallic interconnects and the Ni-current collector on DA-SOFC operation within the temperature range of 650 degrees C - 750 degrees C. The anode components, including the metallic interconnect, Ni-current collector, and the SOFC cell, are investigated in powder form and in DA-SOFC operation to determine each component ' s influence under actual DA-SOFC operating conditions. Both Fe-rich and Ni-rich high-temperature alloys demonstrate high catalytic activity for the ammonia decomposition reaction, playing a significant role in actual cell operations. Furthermore, extensive impedance analysis of DA-SOFC operation under various fuel conditions reveals that residual ammonia significantly increases polarization resistance at lower temperatures, which is the primary factor contributing to negative effect on performance at these temperatures. English Pergamon Press Ltd. Characterization of direct-ammonia solid oxide fuel cells (DA-SOFCs) at 650-750 °C in a single-repeating unit stack: Effects of metallic components and residual ammonia Article 10.1016/j.ijhydene.2024.04.250 1 International Journal of Hydrogen Energy, v.68, pp.1312 - 1321 International Journal of Hydrogen Energy 68 1312 1321 Y scie scopus 001237702200001 2-s2.0-85192102963 Chemistry, Physical Electrochemistry Energy & Fuels Chemistry Electrochemistry Energy & Fuels Article HYDROGEN-PRODUCTION DECOMPOSITION PERFORMANCE ENERGY ANODE CATALYSTS GENERATION OXIDATION ELECTRODE STRESS Solid oxide fuel cell Direct ammonia solid oxide fuel cell Ammonia decomposition Ammonia Catalysis