EFFECTS OF CERIA ADDITION ON NI/YSZ ANODES FOR SOFC'S OPERATING WITH SYNGAS AND N-BUTANE

摘要

This study explores the incorporation of ceria (CeO_2) into Ni/YSZ cermet anodes for solid oxide fuel cell performance with both syngas and n-butane/steam feeds to suppress carbon deposits and expand operability of Ni-based anodes with carbonaceous fuel feeds. CeO_2 was co-fired with Ni/YSZ cermets to form a porous anode support layer (1 mm thick), which was tested in SOFC button cells with dense YSZ electrolytes (10-20 μm thick) and porous LSM/YSZ cathodes (～50 μm thick). The co-fired Ni/CeO_2/YSZ anode-supported cells were tested from 700 to 800 ℃ on various fuels including syngas and n-butane with H_2O added at a 1.5-to-1 and a 1 -to-1 steam-to-carbon (S/C) ratio. Electrochemical characterization revealed that CeO_2 addition provided stable performance with high power densities at 800 ℃ - up to 0.6 W/cm~2 on syngas and 0.35 W/cm~2 on direct butane feeds - without significant carbon deposition as observed for Ni/YSZ anodes without CeO_2. Testing with syngas at different H_2 and CO partial pressures indicated that high power densities can be maintained along an anode channel for up to 50% fuel conversion. The results indicate that CeO_2 addition to Ni/YSZ may provide a viable means for stable SOFC operation on either pre-reformed or direct light-hydrocarbon fuel feeds.