Ethylene glycol as a new sustainable fuel for solid oxide fuel cells with conventional nickel-based anodes

In this study, renewable ethylene glycol (EG) was exploited as a potential fuel for solid oxide fuel cells (SOFCs) with conventional nickel yttria-stabilized zirconia (Ni-YSZ) cermet anodes for sustainable electric power generation. Carbon deposition behaviors over Ni-YSZ anodes under different carbon-containing atmospheres such as EG, glycerol, ethanol and methane were characterized through thermodynamic prediction, oxygen-temperature programmed oxidation and SEM-EDX analysis. EG was observed to be better than acetic acid and glycerol and much better than methane and ethanol in terms of carbon deposition. A calculation of the open-circuit voltages of EG-fueled SOFCs suggested that EG is a suitable fuel for SOFCs. A maximum power output of 1200mWcm^-2 at 750°C was obtained from a cell operating on EG-steam fuel, which is only a little lower than that from a cell based on hydrogen fuel. The cell was further operated stably on an EG-steam gas mixture for 200h with no apparent performance degradation, carbon deposition over the anode, Ni agglomeration, or change in the morphology of the anodes. The current study confirmed the practical applicability of EG as a direct fuel for SOFCs, which may have a great effect on future energy systems.