80 Hours operation of a tubular solid oxide fuel cell using propane/air

High power density and simple design are vital for these fuel cell-based portable power generation devices. This study provides an 8.6 g tubular SOFC with embedded a catalytic partial oxidation reformer, which is fabricated and operated for more than 100 h using propane/air. Nickel-iron nanosheets, as catalysts for reforming, supported on α-Al₂O₃ foam ceramic are synthesized by hydrothermal treatment. Testing for 80 h gives a power degradation of about 20% compared with the initial value. It is mainly attributed to sulfur-poisoning of nickel near anode/electrolyte interface according to transmission electron microscope (TEM) analysis. From TEM/energy dispersive spectroscopy line-scan results across the anode/electrolyte interface, sulfur as either aggregate at the nickel/yttria-stabilized zirconia grain boundaries or on the nickel grain surface, and no obvious carbon phase is founded. The maximum power density is 0.67 W cm⁻² at 700 °C using propane/air (12 vol% propane), about 5% higher than the same cell using 20 vol% hydrogen.