To replace Pt-based catalysts for oxygen reduction reactions in polymer electrolyte membrane fuel cells, various carbon nanostructures doped by transition metals and heteroatoms have been investigated. In this study, we synthesized bi-modal porous iron and nitrogen doped carbon nanostructures as non precious metal catalysts using glycine as a dopant and carbon source in the presence of iron salt. The samples exhibited a bi-modal porous structure consisting of macro- and meso-pores of 500 and 20 nm, respectively, and specific surface areas of 214-740 m(2) g(-1), which facilitate electrochemical reactions due to increased amounts of electrochemical active sites and favorable mass transport. Furthermore, the porous carbon nanostructures showed considerable amounts of dopants, high crystallinity, and excellent electrical conductivity. Especially, the sample prepared using 500 and 20 nm silica beads with both glycine and iron salt showed improved catalytic activity in both acidic and alkaline media comparable to that of a commercial Pt catalyst. (C) 2017 Elsevier B.V. All rights reserved.