Insights into Nitrogen-doped Carbon for Oxygen Reduction: The Role of Graphitic and Pyridinic Nitrogen Species

Authors：Wang, Dongliang^*; Hu, Jingping; Wei, Junjie; Liu, Xianli; Hou, Huijie^*

Source：Chemphyschem : a European journal of chemical physics and physical chemistry , 2023, 24(10).

DOI：10.1002/cphc.202200734

• nitrogen-doped carbon
• graphitic N
• pyridinic N
• oxygen reduction reaction
• density functional calculations

Nitrogen-doped carbons (N/Cs) manifest good catalytic performance for oxygen reduction reaction (ORR) for fuel cell systems. However, to date, controversies remain on the role of active sites in N/Cs. In the present study, ORR test was conducted on three N/Cs in O-2-saturated 0.1 M KOH aqueous solution, where apparent linear correlation between graphitic N contents and ORR activity was observed. Theoretical calculations demonstrated that graphitic N doping is energetically more favorable than that of pyridinic N doping for ORR and the pyridinic N leads to more preferential with 2 e(-) ORR pathway. These results reveal that graphitic N plays a key role in N/Cs mediated ORR activity. This work lays a solid foundation on identifying the active sites in heteroatom-doped carbons and can be exploited for rational design and engineering of effective carbon-based ORR catalysts.

• Institution
  华中科技大学