Adaptation of Ni_0.6Cu_0.4/Ce_0.9Gd_0.1O_1.95 cermet anodes for intermediate temperature solid oxide fuel cells to actual biogas fuel containing trace amounts of H₂S: Effects of catalyst amount and fuel supply rate

Abstract

Adaptation of Ni_0.6Cu_0.4/Ce_0.9Gd_0.1O_1.95 cermet anodes for intermediate temperature solid oxide fuel cells (IT-SOFCs) for direct use of biogas fuel containing trace amounts of H₂S was investigated at 700 °C. The catalyst amount and fuel supply rate were investigated based on the stable power generation conditions achieved with simulated biogas. The catalyst amount was increased by enlarging the electrode area and anode thickness to produce a tri-layered anode. The influence of H₂S poisoning was mitigated and the stability of the power generation performance was improved. However, increasing the amount of catalyst caused an increase in carbon deposition on the anodes. When the fuel supply rate was decreased, carbon deposition was suppressed and the amount of H₂S supplied was also reduced, further improving the stability of the power generation performance, sustainable for 24 h. These results are expected to provide important insights into the practical applications of IT-SOFCs that directly use biogas as a fuel.