@article{Cai2021, 
author = {Huizhu Cai and Bingbing Chen and Xiao Zhang and Yuchen Deng and Dequan Xiao and Ding Ma and Chuan Shi},
title = {Highly active sites of low spin FeⅡN4 species: The identification and the ORR performance},
year = {2021},
journal = {Nano Research},
volume = {14},
number = {1},
pages = {122-130},
keywords = {oxygen reduction reaction, electrocatalysis, single sites of FeN4, structure-performance correlation},
url = {https://www.sciopen.com/article/10.1007/s12274-020-3054-8},
doi = {10.1007/s12274-020-3054-8},
abstract = {Over recent years, catalytic materials of Fe-N-C species have been recognized being active for oxygen reduction reaction (ORR). However, the identification of active site remains challenging as it generally involves a pyrolysis process and mixed components being obtained. Herein Fe3C/C and Fe2N/C samples were synthesized by temperature programmed reduction of Fe precursors in 15% CH4/H2 and pure NH3, respectively. By acid leaching of Fe2N/C sample, only single sites of FeN4 species were presented, providing an ideal model for identification of catalytic functions of the single sites of FeN4 in ORR. A correlation was conducted between the concentration of FeⅡN4 in low spin state by Mössbauer spectra and the kinetic current density at 0.8 V in alkaline media, and such a structure-performance correlation assures the catalytic roles of low spin FeⅡN4 species as highly active sites for the ORR.}
}