Modulate FeCo Nanoparticle in situ Growth on Carbon Matrix for High-Performance Oxygen Catalysts

Abstract Fe-Co bimetallic electrocatalysts show tremendous promise for both oxygen reduction (ORR) and evolution reaction (OER) in alkaline medium to replace precious metal catalysts. Here, we report a successful size modulation strategy for FeCo binary alloys in-situ growth on carbon matrix. Analogous to Pt nanoparticles, the size modulation could give rise to increased active sites in FeCo-based catalysts without altering their chemical properties. The compositionally optimized template with abundant carbon nanotubes and uniform distribution of FeCo alloy nanoparticles, exhibits superior electrocatalytic activity by achieving a high-performance half-wave potential of 0.88 V toward ORR as well as robust stability after 10 000 cycles. The open-circuit potential (Voc) of liquid Zn-air battery is close to 1.40 V which is comparable with that of Zn-air battery equipped with Pt/C+IrO2. Our findings offer new prospects for understanding metal particle sizes and electrocatalytic performance of pyrolyzed transition metal-carbon materials.