A low-cost,highly active,stable,and methanol tolerant electrocatalyst towards the oxygen reduction reaction(ORR)is extremely desirable for promoting the commercialization of fuel cells.Herein,we reported a facile two-step pyrolysis and acid leaching process to synthesize a high performance ORR electrocatalyst,where ultra-small Fe2N nanocrystals were incorporated into mesoporous nitrogen-doped graphitic carbon spheres(MNGCS).The Fe2N/MNGCS electrocatalysts with difference Fe2N contents and BET surface areas were obtained via altering the acid leaching time,and all exhibited the apparent electrocatalytic activity.The optimized ORR activity was achieved over(Fe2N/MNGCS)4 with the positive half-wave potentials(0.881 V vs RHE),high selectivity(4 e-process),excellent long-term stability(95.2%of the initial current remaining after 60000s of continuous operation)and good tolerance against methanol-crossover effect(94.9%of the current retained prior to 4.0 M methanol injection)in alkaline media,which even was more superior to that of commercial Pt/C catalyst.The remarkable ORR activity was originated from the cooperative effect of ultra-small Fe2N nanocrystals and MNGCS,where the balance of catalytic active site density,mesoporous structure,BET specific surface area,and electron conductivity played a key role in determining the ORR performance.