A highly efficient metal-free N-doped carbon electrocatalyst toward oxygen reduction was obtained by one-pot pyrolysis of a single Zn(II)-MOF with mixed azolate and terephthalate ligands, demonstrating E1/2 of 0.88 V (vs. RHE) in 0.1 M KOH, and 0.79 V (vs. RHE) in 0.5 M H2SO4. It represents one of the best metal-free N-doped carbon electrocatalysts for the acidic ORR.