Scalable Zn Single Atom-Gluing Ru for 75-W-Scale Alkaline Membrane Fuel Cell Stacks

Anion exchange membrane fuel cells (AEMFCs) have caught widespread attention as a next-generation low-cost hydrogen conversion technology. However, the AEMFC technology is still in its infancy, and there are rarely reports of cost-effective AEMFC stacks. Therefore, it is imperative yet significantly challenging to develop Pt-free, highly active, and durable hydrogen oxidation reaction (HOR) catalysts for AEMFC stack applications. Here, we present a scalable Zn single atom-gluing Ru nanoparticle on a Zn-N-C support (Ru@Zn-N-C) in which the incorporation of Zn single atoms substantially boosts H₂ adsorption and stabilizes Ru nanoparticles. Consequently, the 10-g-scale Ru@Zn-N-C achieves an unprecedented peak power density (PPD) of 2.10 W cm^-2 and a record-breaking anode specific power of 42 W mg^-1 with an ultralow Ru loading of 0.05 mg cm^-2 in a single AEMFC. Meanwhile, the rated power density of the Ru@Zn-N-C-based fuel cell (1.24 W cm^-2@0.65 V in H₂-air) fulfills the US Department of Energy (DOE) target for 2025 (1 W cm^-2, ≤0.125 mg_PGM cm^-2 loading), and the fuel cell can be operated stably at 1 A cm^-2 for over 200 h, significantly outperforming the state-of-the-art AEMFCs. Most importantly, we develop cost-effective three-cell AEMFC stacks that can achieve an exceptional rate power of approximately 75 W in H₂-O₂ with an ultralow Ru loading of 0.05 mg cm^-2, which can project only 8 g Ru utilization for a 100 kW fuel cell vehicle, surpassing the ultimate US DOE target of 0.1 g_Pt kW^-1 for urban transportation.