Non-noble catalysts for the oxygen reduction reaction (ORR) are in high demand for fuel cell technology due to their use of low cost and widely available starting materials. The development of these catalysts has been a constantly growing area. However, to the extent of our knowledge, there have only been a few literature reports that provide insights into the nature of the structure and geometry of the catalytically active sites formed in these materials.In the current literature, the most commonly proposed catalytically active site(s) for ORR are active sites that correspond to Fe-N2+2/C geometry. These active sites are typically produced through a high-temperature pyrolysis step to obtain this desired configuration[1]. However, the pyrolysis step is very disadvantageous due to the production of a variety of nitrogen functional groups on the surface which can negatively affect the activity of the catalyst, since only nitrogen functionalities with specified geometry are considered to be the most active for ORR[2,3]. In addition, high-temperature treatments drastically increases the overall cost of production and can be quite energy demanding. Thus, high-temperature treatment makes it difficult to design a surface rich in a specific active site for the desired application.We had previously developed a model of a catalyst rich in Fe-N3/C sites on a commercial Vulcan carbon. We showed that this site had high activity for the ORR reaction achieved by covalently functionalizing a carbon support with a nitrogen-rich terpyridine (tpy) ligand. The ligand geometry allowed for the formation of well-defined active sites on the carbon surface, leaving exposed N3 moities for the ORR. Metal-ligand coordination with Fe resulted in desired Fe-N3/C moieties on the surface. We demonstrated that this system can be prepared using mild reaction conditions and does not require high-temperature treatment for improved activity. On the contrary, the heat-treatment to this system was detrimental to the activity. Recently, we have been investigating the effect of other non-precious late transition metals for the activity of the novel N3/C sites. We present here the results of the M-N3/C site where M= Co, Sn, Ni, or Mn and show that these metals also show promising electrochemical activity in both acidic and basic media due to well-defined N3/C site for the ORR, showing generality of our initial results with iron and overall versatility and activity of an N3 site in combination with various non-precious metals for an ORR catalyst.[1] M. Lefèvre, E. Proietti, F. Jaouen, J.-P. Dodelet, Science 2009, 324, 71-74.[2] F. Charreteur, F. Jaouen, S. Ruggeri, J.-P. Dodelet, Electrochimica acta 2008, 53, 2925-2938.[3] H. M. Fruehwald, I. I. Ebralidze, O. V. Zenkina, E. B. Easton, ChemElectroChem 2019, 6, 1350. Figure 1