Mesoporous Fe‐N x ‐C Sub‐Microspheres for Highly Efficient Electrocatalytic Oxygen Reduction Reaction

We design and obtain mesoporous Fe‐N x ‐C sub‐microspheres (Meso Fe‐N x ‐C‐SS) using the amino acid‐metal complex as Fe/N/C precursor and mesoporous silica sub‐microspheres (MSS) as hard template by a facile template‐assistance strategy. The Histidine‐Fe complex is impregnated into mesopores of MSS, and then Meso Fe‐N x ‐C‐SS are obtained by high‐temperature carbonization process and removal of MSS template. The as‐fabricated Meso Fe‐N x ‐C‐SS exhibits the spherical structure with rough surface with the diameter size of 200–500 nm. And Meso Fe‐N x ‐C‐SS also possesses a high specific surface area of 784 m 2  g −1 , a large pore volume of 1.65 cm 3  g −1 , and a large pore size in the range of 10–22 nm. Benefiting from atomically dispersed N‐coordinated Fe and unique three‐dimensionally (3D) interconnected mesoporous carbon architecture, Meso Fe‐N x ‐C‐SS shows excellent electrocatalytic performance toward oxygen reduction reaction (ORR) with positive half‐wave potential (E 1/2 0.86 V), high stability (93.94 % after 30,000 s), low Tafel slop (43 mV dec −1 ) and good methanol tolerance, exceeding commercial Pt/C catalyst in alkaline media. As the cathode catalyst within the primary Zn‐air batteries, Meso Fe‐N x ‐C‐SS also reveals an outstanding catalytic activity (the maximum power density of 120 mW cm −2 ) and superior discharge stability (at current density of 10 mA cm −2 after 6 cycles, at different current densities of 5, 10, 20 mA cm −2 ), promoting its practical application in Zn‐air batteries.