Catalytic Activity Determination of Pyridinic-N-Doped Carbon Materials and Relationship between Catalytic Activity and Pyridinic-N Position in Oxygen Redox Reaction

N-doped carbon-based materials (NCMs) have exhibited outstanding catalytic performance in the oxygen redox reaction. However, the majority of N doping methods results in the coexistence of multiple N species with an uncertain N position and content, which makes the attribution of nitrogen atom catalytic activity inconsistent. This report illustrates the indispensable role of graphdiyne (GDY) in constructing NCMs that contain only pyridinic-N with a clear location and content. Thus, a series of catalysts were constructed to reveal the intrinsic activity of NCMs after pyridinic-N doping and the relationship between the pyridinic-N position and catalytic activity. Electrochemical characterization revealed its bifunctional catalytic activity and better 2e- oxygen evolution reaction (ORR) performance that increases with N content, while pyridinic-N atoms at the edge position exhibit higher catalytic efficiency than basal ones. In addition, excellent long-term stability in catalysis was obtained. Density functional theory (DFT) calculation suggested that carbon adjacent to nitrogen at the edge possessed the lowest reaction energy barrier and should serve as a 2e- ORR active center. This study demonstrates that GDY is irreplaceable in examining the intrinsic activity of NCMs of designated heteroatom doping, which could be extended to other fields of application.