Atomically Dispersed Zn-Pyrrolic-N₄ Cathode Catalysts for Hydrogen Fuel Cells

To achieve practical application of fuel cell, it is vital to develop highly efficient and durable Pt-free catalysts. Herein, we prepare atomically dispersed ZnNC catalysts with Zn-Pyrrolic-N-4 moieties and abundant mesoporous structure. The ZnNC-based anion-exchange membrane fuel cell (AEMFC) presents an ultrahigh peak power density of 1.63 and 0.83 W cm(-2) in H-2-O-2 and H-2-air (CO2-free), and also exhibits long-term stability with more than 120 and 100 h for H-2-air (CO2-free) and H-2-O-2, respectively. Density functional calculations further unveil that the Zn-Pyrrolic-N-4 structure is the origin of high activity of as-synthesized ZnNC catalyst, while the Zn-Pyridinic-N-4 moiety is inactive for oxygen reduction reaction (ORR), which successfully explain the puzzle why most Zn-metal-organic framework -derived ZnNC catalysts in previous reports did not present good ORR activity because of their Zn-Pyridinic-N-4 moieties. This work offers a new route for speeding up development of AEMFCs.