Boost the Utilization of Dense <scp>FeN₄</scp> Sites for High‐Performance Proton Exchange Membrane Fuel Cells

Iron‐nitrogen‐carbon (Fe‐N‐C) catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) have seriously been hindered by their poor ORR performance of Fe‐N‐C due to low active site density (SD) and utilization. Herein, we reported a melamine‐assisted vapor deposition approach overcome these hindrances. The melamine not only compensates loss nitrogen caused high‐temperature pyrolysis but also effectively etches carbon substrate, increasing external surface area mesoporous porosity substrate. These can provide more useful subsequent on sites. prepared 0.20Mela‐FeNC catalyst shows fourfold higher SD value utilization than FeNC without treatment melamine. As result, exhibits high activity with half‐wave potential ( E 1/2 ) 0.861 V 12‐fold mass acidic media. cathode H 2 ‐O PEMFCs, demonstrates peak power 1.30 W cm −2 , outstripping most catalysts. developed boosting offers new insight into high‐performance electrocatalysts.