Iron- and Nitrogen-Containing Carbon Nanotube/Carbide-Derived Carbon-Based Electrocatalysts for Oxygen Reduction Reaction in Acidic Conditions

In this work, iron- and nitrogen-doped carbide-derived carbon and carbon nanotube (CDC/CNT) composites are prepared and used as oxygen reduction reaction (ORR) electrocatalysts in acidic conditions. Three different approaches are taken to mix iron and nitrogen precursors, namely iron(II) acetate and 1,10-phenanthroline, with the nanocarbon materials. The doping is done via high-temperature pyrolysis. The success of doping is proved by several physicochemical methods indicating that iron is atomically dispersed. The Fe−N−C catalyst materials possess similar textural properties with high specific surface area and plenty of pores in different sizes. The evaluation of the ORR activity using the rotating (ring−)disk electrode method shows that the prepared Fe−N−C materials have very similar and good electrocatalytic performance in acidic media and low yield of H₂O₂ formation. This excellent ORR performance of the Fe−N−C catalyst materials is attributed to the presence of Fe−N_x and pyridinic-N moieties, as well as a feasible porous structure.