FeOy@graphitic carbon core–shell nanoparticles loaded on two dimensional carbon nanosheets with exclusive Fe-Nx moieties for efficient oxygen reduction reaction

Fe-based nanoparticles encapsulated in carbon can effectively promote the ORR activity of the neighboring Fe–N x and prevent the dissolution of metal nanoparticles to ensure the long-term durability of catalysts. Herein, we employed a facile two step pyrolysis strategy to construct “plane-active sites” structure, namely FeO y nanoparticles embedded in carbon were loaded on two dimensional (2D) porous carbon with exposed abundant Fe–N x active sites (FeOy@C/Fe-N x /C). The optimized FeO y @C/Fe-N x /C catalyst with low Tafel slope (48 mV dec −1 ) and nearly-four-electron selectivity (3.91–3.97) showed excellent performance towards ORR with a more positive shift of 15 mV of half-wave potential (E 1/2  = 0.856 V) than that of commercial Pt/C (E 1/2  = 0.841 V) in alkaline solution, and also had a superior long-term stability and methanol resistance as compared with commercial Pt/C. The excellent electrochemical performance of FeO y @C/Fe-N x /C can be attributed to FeO y @C structure, exposed abundant Fe–N x active sites and two dimensional porous carbon with a large specific surface area.