Study of Carbon Deposition Behavior on Cu–Co/CeO2–YSZ Anodes for Direct Butane Solid Oxide Fuel Cells

Abstract

AbstractElectro‐catalytic activity of Cu–Co/CeO2–YSZ anodes towards oxidation of H2 and n‐C4H10 fuels and carbon depositions are investigated using different Cu–Co loadings. Cu–Co/CeO2–YSZ anode based SOFCs with YSZ as electrolyte and LSM/YSZ as cathode were prepared by tape casting and wet impregnation methods and performance was analyzed using I–V characteristics and impedance spectroscopy. The Cu–Co/CeO2–YSZ anodes with Cu–Co loading of 10, 15, and 25 wt.% produced power density of 60, 197, and 400 mW cm–2 in H2 and 190, 225, and 275 mW cm–2 in n‐C4H10 at 800 °C. The power density is increased with the increase in Cu–Co loading in Cu–Co/CeO2–YSZ anodes. The electrochemical impedance spectra shows less ohmic and polarization resistance for 25 wt.% Cu–Co loading in comparison to 10 and 15 wt.% Cu–Co. Scanning electron microscopy and high resolution transmission electron microscopy shows that the carbon fibers formed are hollow in nature with 70 nm size, whereas, thermal gravimetric analysis and X‐ray diffraction points out that they are amorphous in nature. The performance degradation of Cu–Co/CeO2–YSZ anodes in n‐C4H10 in 16 h is attributed to increasing amount of carbon deposition with time, which is contrary to our earlier observation in Cu‐Fe/CeO2–YSZ anode.