Performance Factors and Sulfur Tolerance of Metal Supported Solid Oxide Fuel Cells with Nanostructured Ni:GDC Infiltrated Anodes

Two metal supported solid oxide fuel cells (active area 16 cm 2 ) with nanostructured Ni:GDC infiltrated anodes, possessing different anode and support microstructures were studied in respect to sulfur tolerance at an operating temperature of 650 • C. The studied MS-SOFCs are based on ferretic stainless steel (FeCr) and showed excellent performance characteristics at 650 • C with fuel utilization corrected area specific resistances of 0.35 cm 2 and 0.7 cm 2 respectively.The sulfur tolerance testing was performed by periodic addition of 2, 5, and 10 ppm H 2 S in hydrogen based fuel under galvanostatic operation at a current load of 0.25 Acm -2 .The results were compared with literature on the sulfur tolerance of conventional SOFC Ni/YSZ cermet anode.The comparison in terms of absolute cell resistance increase and relative anode polarization resistance increase indicates, that the nanostructured Ni:GDC MS-SOFC based anode is significantly more sulfur tolerant than the conventional Ni/YSZ cermet anode.Furthermore, it was shown that the believed extension of the electrochemical three-phase-boundary reaction zone in the presence of GDC must be very limited and cannot account for the higher sulfur tolerance of GDC modified SOFC anodes.