Pore-rich iron-nitrogen-doped carbon nanofoam as an efficient catalyst towards the oxygen reduction reaction

Developing cost-effective electrocatalysts is crucial for oxygen reduction reactions. In this work, a highly active iron-nitrogen co-doped carbon nanofoam is proposed and developed via a facile salt-assisted pyrolysis process of chitooligosaccharides. i) Chitooligosaccharides, a nitrogen-rich polymer with high water solubility and high thermostability, induce a coordination reaction between iron ions and amino/hydroxyl groups, forming large active sites. ii) FeCl₃/KCl salt, acting as a template, etching agent and catalyst for graphitization, facilitates the formation of pore-rich carbon, leading to enhanced mass transfer and electronic conduction. It has been found that this iron-nitrogen co-doped carbon nanofoam presents competitive activity over commercial Pt/C, as follows: i) a high onset potential approximately 0.965 V, ii) strong durability with a current retention rate of 88% after 30000 s, and iii) excellent fuel tolerance to methanol, ethanol and formate. This work provides a simple, low-cost and environmentally friendly method to prepare iron-nitrogen co-doped carbon materials that has great potential to be extended to other catalysts for energy-related applications.