Ordered Hierarchically Porous Carbon Codoped with Iron and Nitrogen As Electrocatalyst for the Oxygen Reduction Reaction

Abstract

Nitrogen-doped carbon catalysts have attracted great attention as potential alternatives to the expensive Pt-based catalysts used in fuel cells. Herein, a novel catalyst based on nitrogen and iron co-doped ordered hierarchically porous carbon (Fe-NOHPC) is prepared via an evaporation-induced self-assembly process, followed by carbonization under an ammonia atmosphere. The soft template and the Fe species are found to promote the formation of the NOHPC structure and facilitate the oxygen reduction reaction (ORR) process. The catalyst possesses an ordered hierarchically porous structure with a large surface area (1172.5 cm2 g-1) and pore volume of 1.03 cm3 g-1. Compared to the commercial 20 % Pt/C, it has better ORR catalytic activity and higher stability, as well as higher methanol tolerance in an alkaline medium, demonstrating its potential for use in direct methanol alkaline fuel cells as a non-precious cathode catalyst. The nitrogen configuration, Fe species and pore structure of the catalysts are believed to correlate with its high catalytic activity.