In this combined experimental and theoretical work, electrochemical studies showed that the resulting Fe, N-codoped carbons exhibited enhanced electrocatalytic activity toward oxygen reduction in alkaline media as compared to the counterparts doped with nitrogen alone (link).
Bingzhang Lu, Tyler J. Smart, Dongdong Qin, Jia En Lu, Nan Wang, Limei Chen, Yi Peng, Yuan Ping and Shaowei Chen, “Nitrogen and Iron-Codoped Carbon Hollow Nanotubules as High-Performance Catalysts toward Oxygen Reduction Reaction: A Combined Experimental and Theoretical Study”, Chem. Mater. 29, 5617-5628 (2017).