Efficient and durable ammonia power generation by symmetric flat-tube solid oxide fuel cells

Abstract

Ammonia as an alternative fuel of hydrogen for solid oxide fuel cells is attractive owing to its low cost, ease for transportation and storage, and non-carbon emission. In this work, NH3 power generation was carried out using a flat-tube SOFC with symmetric double-sided cathodes (DSC). The cell performance and durability as well as the catalytic activity of NH3 decomposition within the anode were evaluated simultaneously. The power density of NH3-fueled DSC reached 195 mW cm−2 at 750 °C, which was close to that of H2-fueled one (198 mW cm−2). No apparent degradation of the NH3-fueled DSC cell was observed after stability test for 120 h at 750 °C. In addition, the DSC cell constantly fed with NH3 exhibited stable open circuit voltages throughout a thermal cycling test between 550 and 750 °C for 15 cycles, indicating that no microstructural damage was caused by such severe operation condition. Furthermore, it was found that adding extra catalyst into the inner channels of the anode support promoted the NH3 conversion rate in DSC cell from 83% to 95% at 750 °C, which agreed with the theoretical calculation results. These results demonstrated the promising prospect of the DSC for efficient and durable ammonia power generation.