High-performing commercial Fe–N–C cathode electrocatalyst for anion-exchange membrane fuel cells

To reduce the cost of fuel cell stacks and systems, it is important to create commercial catalysts that are free of platinum group metals (PGMs). To do this, such catalysts must have very high activity, but also have the correct microstructure to facilitate the transport of reactants and products. Here, we show a high-performing commercial oxygen reduction catalyst that was specifically developed for operation in alkaline media and is demonstrated in the cathode of operating anion-exchange membrane fuel cells (AEMFCs). With H2/O2 reacting gases, AEMFCs made with Fe–N–C cathodes achieved a peak power density exceeding 2 W cm−2 (>1 W cm−2 with H2/air) and operated with very good voltage durability for more than 150 h. These AEMFCs also realized an iR-corrected current density at 0.9 V of 100 mA cm−2. Finally, in a second configuration, Fe–N–C cathodes paired with low-loading PtRu/C anodes (0.125 mg PtRu per cm2, 0.08 mg Pt per cm2) demonstrated a specific power of 10.4 W per mg PGM (16.25 W per mg Pt). Highly active oxygen reduction catalysts that are free of platinum group metals would decrease the cost of fuel cells. Here, the authors report on a commercial Fe–N–C-based catalyst that can replace platinum group metal-based catalysts in the cathodes of anion-exchange membrane fuel cells without a severe loss of performance.