**4.1.1 SOFC single cell used in the tests**

Ni-yttria stabilized zirconia cermet (Ni-YSZ) is the most popular material for SOFC anodes. However, it has been reported that Ni-scandia stabilized zirconia (Ni-ScSZ) offers better catalytic performance and can suppress coking when hydrocarbon fuels are supplied to SOFC (Ke et al., 2006). Thus, we used anode-supported type cells based on the anode/electrolyte bilayer (half cell) of Ni-ScSZ/ScSZ to evaluate the electrochemical and catalytic performance of IRSOFCs operating on biofuels (*Bio*-SOFCs). Two types of half cells, button cell with diameter of 20 mm and square-shaped cells with area of 5 x 5 cm2 purchased from Japan fine ceramics were used to fabricate single cells. The cells consist of ScSZ electrolyte with a thickness of 14 m sintered on a porous anode support (mixture of NiO and ScSZ (NiO:ScSZ = 5.6:4.4)) with a thickness of 800 m. A mixture of (La0.8Sr0.2)0.98MnO3 (> 99.9 %, Praxair, USA, abbreviated by LSM) and ScSZ (Daiichi Kigenso Kagaku Kogyo, Japan) with a weight ratio of 1:1 was adopted as a cathode functional layer and coarse LSM was applied as a cathode current collector layer. Porous cathodes with the area of 0.8 x 0.8 and 4 x 4 cm2 for button and square-shaped cells, respectively, were obtained by sintering process at 1200 oC for 3 h. Component materials of the single cells were summarized in Table 3.


Table 3. Component materials of the anode-supported single cells (Shiratori et al., 2010b).
