Development of Direct-Ammonia Solid Oxide Fuel Cells (DA-SOFCs) and the Effect of Incorporating Internal Ammonia Decomposition Catalysts

Abstract

Direct-ammonia solid oxide fuel cells (DA-SOFCs) are among the most efficient power sources that use ammonia. The high operating temperature of SOFCs enables ammonia decomposition reaction to proceed inside the anode compartment of SOFCs. Coupling exothermal SOFC operation and endothermal ammonia decomposition reaction increases the efficiency of the device. DA-SOFCs function as well as hydrogen-fueled ones over 750 °C. Recently we have reported that DA-SOFCs suffer significant performance loss under 650 °C, especially the high-performance cells. We discuss a range of phenomena taking place inside the anode compartment of DA-SOFCs: interconnect, current collector, and anode support. Interconnect and current collector have the capability of decomposing significant amounts of ammonia. Nevertheless, incorporating a catalyst is important at low operating temperatures.