Improving the catalytic activity and sintering resistance of Ni-BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3−δ cermet anode for ammonia-fueled protonic ceramic fuel cells via Cobalt addition

Ammonia-fueled protonic ceramic fuel cells (PCFCs) are emerging as promising alternatives to H₂-fueled PCFCs, offering advantages such as higher energy density and enhanced safety. However, their widespread application is impeded by challenges, including insufficient catalytic activity towards ammonia and limited stability of the anode structure. Herein, we report a rational design for Ni₉₇Co₃-BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3−δ (BCZYYb) cermet anodes, aimed at enhancing both catalytic activity and durability for ammonia utilization. The cell featuring the Ni₉₇Co₃-BCZYYb anode leverage the synergistic interaction between Ni and Co to enhance ammonia adsorption and nitrogen desorption, resulting in a remarkable 67.8 % increase in power density when operating with NH₃ at 600 °C. Notably, upon switching the fuel from H₂ to NH₃, this achieves an unprecedented power retention of 87.2 % at 700 °C, representing one of the highest values recorded for ammonia-fueled PCFCs, while most ammonia-fueled cells exhibit power retention in the range of only 60–80 %. Furthermore, the cell with Ni₉₇Co₃-BCZYYb cermet anode demonstrates exceptional durability, stable operation over 30 h at 650 °C under NH₃ with no degradation observed. This longevity is attributed to the excellent sintering resistance of the NiCo alloy, highlighting the potential of the Ni₉₇Co₃-BCZYYb cermet anode for long-term applications. This work provides an effective strategy for designing highly active and durable anodes for ammonia-fueled PCFCs.