Iron Single Clusters Anchored on N‐Doped Porous Carbon as Superior Trace‐Metal Catalysts toward Oxygen Reduction

Abstract A new strategy to in situ immobilize iron (Fe) single clusters on N‐doped porous carbon under the confinement effect of N‐coordination supplied by porphyrins is demonstrated. During the pyrolysis reaction, the strong chelated interaction between Fe and N atoms serves as the pivotal role for achieving Fe single clusters via inhibiting the superabundant aggregation of Fe atoms. Compared to the Fe‐based nanoparticles and commercial Pt‐C, the synthesized single Fe cluster catalyst (C/TP‐Fe700) owns a superior catalytic performance in alkaline medium, which is confirmed by the more positive half‐wave potential (0.865 V, 28 mV higher than Pt‐C), high mass activity (0.60 A mg −1 Fe , 10 times larger than Pt‐C), the excellent durability and remarkable methanol tolerance. Additionally, it likewise presents satisfactory oxygen reduction reaction activity in acidic medium compared with Pt‐C. This single metal cluster (metal cluster with subnanometer) catalyst with trace‐metal contents displays double advantages from metal and metal‐free oxygen reduction catalysts, such as high activity, ultralight mass, and environmental friendliness. Insight into this successful paradigm can provide a novel concept for constructing and understanding oxygen reduction catalysts at an approximate atomic scale.