An Efficient and Durable Anode for Ammonia Protonic Ceramic Fuel Cells

Ammonia protonic ceramic fuel cells (PCFCs) have potential to be a highly efficient power source of high energy density. However, the inadequate catalytic activity of the existing anodes for utilization of ammonia greatly limits the performance of PCFCs. Here we report a Fe-modified state-of-the-art Ni cermet anode with greatly enhanced activity and durability toward utilization of ammonia. Cells with a Fe-decorated Ni-BaZr0.1Ce0.7Y0.1Yb0.1O3 (Ni-BZCYYb) anode demonstrate an excellent performance, achieving peak power densities of 0.360, 0.723, 1.257, and 1.609 Wcm−2 at 550, 600, 650, and 700 oC, respectively, which are the highest performance of solid oxide fuel cells fueled on ammonia. In addition, the cells show an excellent durability when operated at a constant current density of 0.5 A cm−2 (or power density of ~0.435 Wcm−2) at 650 oC. The superior activity and durability of the Fe-modified Ni/BZCYYb anode is attributed to the alternation of NH3 adsorption strength and N2 desorption barrier heights, as confirmed by first-principles based mechanistic and microkinetic modeling. Our research provides a valuable guidance for the development of efficient electro-catalysts for ammonia PCFCs.