Highly-defective Fe-N-C catalysts towards pH-Universal oxygen reduction reaction

The defect engineering of nonprecious metal catalysts (NPMCs) is of significance to advance the oxygen reduction reaction (ORR) catalysts for the application of electrochemical energy devices. Herein, a facile H2O2 etching strategy is proposed to design Fe and N co-doped carbon catalysts (Fe-N-C/H2O2). Thanks to the etching of C, the defective carbon (DC) is endowed with robust anchoring ability, which is conducive to the modulation of active sites and microstructures, and further improvement of their ORR performances. Due to the supporting effect, the effective 3D nanostructures can be constructed. Integrated with the composition and morphology features, the resultant Fe-N-C/H2O2 achieves remarkable ORR performance with onset potential of 0.93 V and super stability with a subtle negative shift of 13.1 mV after 20 000 cycles in 0.1 M HClO4. Meanwhile, superior ORR performances are also revealed in alkaline and neutral electrolytes. This work provides an effective strategy for the design of advanced electrocatalysts towards fuel cells.