High-stable porous metal-supported direct ammonia solid oxide fuel cells constructed with plasma-sprayed Fe catalyst layer

Direct ammonia solid oxide fuel cells (DA-SOFCs) have the potential to offer a highly efficient power source with high energy density. Here, we develop a novel porous metal-supported cell specifically designed for DA-SOFCs, demonstrating remarkable electrochemical performance and stability. The full-cell is fabricated by plasma sprayed Ni-based anode, Zr 0.92 Y 0.16 O 2-δ (YSZ) electrolyte, and SrTi 0.3 Fe 0.7 O 3-δ (STF) cathode on a porous 430 steel support, with an additional porous Fe layer on the support surface. This porous Fe layer with fine pores can rapidly catalyze NH 3 decomposition on the support surface, thereby enhancing the cell performance significantly. At 800 °C, when NH 3 serves as the fuel, the peak power density of the cell with an Fe layer reaches 1.24 W/cm 2 , corresponding to 89 % of those achieved using H 2 as fuel. Compared to the cell without Fe layer (1.0 W/cm 2 ), it exhibits a 24 % increase in peak power density. More importantly, the constructed porous steel supported DA-SOFC exhibits excellent stability. When operating at a constant voltage of 0.7 V at 750 °C, the performance degradation rate is lower to 0.002 %/h after 510 h of testing. Moreover, in the gas cycling tests between H 2 and NH 3 , during the 13th cycle, the cell with an Fe layer still maintains high stability, indicating substantial potential for large-scale commercial application.