Correlation between Crystalline Phase of ScSZ and Carbon Deposition Behavior Over Ni-ScSZ Anode for Internal Reforming of Solid Oxide Fuel Cells

Abstract

The influence of preparation condition of Ni-ScSZ (scandia-stabilized zirconia) cermet on the tolerance to carbon deposition was investigated in the wide temperature range of 800-1000ºC. The mixture of NiO-ScSZ was subjected to pre-heat treatments prior to use as a cermet electrode. Although the inhibitory effect of ScSZ in Ni-based cermet for carbon deposition is well-known, the present study revealed that the preparation method and firing condition affected the carbon deposition behavior. The Ni-ScSZ cermet obtained from the oxide mixture heated at 1400ºC showed peculiar behavior to carbon deposition. The initial carbon deposition rate at 800-900ºC for this sample was larger than that at 1000ºC, whereas other samples exhibited a reduction in deposition rate with decreasing temperature. The cubic phase stabilization in ScSZ was confirmed for the sample treated at 1400ºC, though ScSZ was in the rhombohedral phase before the heat-treatment with NiO. These results suggested that a strong interaction between NiO and ScSZ was induced by the high-temperature heat-treatment.