Ni1−xCux alloy-based anodes for low-temperature solid oxide fuel cells with biomass-produced gas as fuel

Ni–Cu alloy-based anodes, Ni1−xCux (x = 0, 0.05, 0.2, 0.3)–Ce0.8Sm0.2O1.9 (SDC), were developed for direct utilization of biomass-produced gas in low-temperature solid oxide fuel cells (LT-SOFCs) with thin film Ce0.9Gd0.1O1.95 electrolytes. The alloys were formed by in situ reduction of Ni1−xCuxOy composites synthesized using a glycine-nitrate technique. The electrolyte films were fabricated with a co-pressing and co-firing technique. Electrochemical performance of the Ni1−xCux–SDC anode supported cells was investigated at 600 °C when humidified (3% H2O) biomass-produced gas (BPG) was used as the fuel and stationary air as the oxidant. With Ni–Cu alloys as anodes, carbon deposition was substantially suppressed and electrochemical performance of the cells was sustained for much longer periods of time. For example, the power export of a Ni–SDC supported cell was only 50% of the initial value (200 mW cm−2 at 0.5 V) after 20 min, while Ni0.8Cu0.2–SDC supported cells could maintain 90% of the initial power density (250 mW cm−2 at 0.5 V) over a period of 10 h. The improved performance of the Ni–Cu alloy-based anodes is worth considering in developing SOFCs fueled directly with dilute hydrocarbons such as gases derived from biomass.