Investigation of Ni-based alloy/CGO electro-catalysts as protective layer for a solid oxide fuel cell anode fed with ethanol

Ni-based alloys were prepared by using the oxalate method and subsequent in-situ reduction. The crystallographic phase and microstructure of the catalysts were investigated. These bimetallic alloys were mixed with gadolinium-doped ceria in order to obtain a composite material with mixed electronic-ionic conductivity. Catalytic and electrocatalytic properties of the composite materials for the conversion of ethanol were investigated. Electrochemical tests were carried out by utilizing the Ni-based alloy/CGO cermet as a barrier layer in a conventional anode-supported solid oxide fuel cell (SOFC). A comparative study between the modified cells and a conventional anode-supported SOFC without the protective layer was made. The aim was to efficiently convert the fuel directly into electricity or syngas (H-2 and CO) just before the conventional anode support. In accordance with the ex-situ catalytic tests, the SOFC anode modified with Ni-Co/CGO showed superior performance towards the direct utilization of dry ethanol than the bare anode and that modified with Ni-Cu/CGO. A peak power of 550 mW cm(-2) was achieved with the dry ethanol-fed Ni-Co/CGO pre-layer modified-cell at 800 A degrees C. A total low frequency resistance of < 0.5 Omega cm(2) at 0.8 V of cell voltage was recorded in the presence of ethanol directly fed to the SOFC.