@article{Shu2021, 
author = {Chengyong Shu and Zhuofan Gan and Yuyang Hou and Ting Zhu and Jijun Ma and Wei Tang and Yuping Wu},
title = {Tailoring the Porous Structure of Mono-dispersed Hierarchically Nitrogen-doped Carbon Spheres for Highly Efficient Oxygen Reduction Reaction},
year = {2021},
journal = {Energy & Environmental Materials},
volume = {4},
number = {1},
pages = {81-87},
keywords = {fuel cells, metal-free catalysts, nitrogen-doped porous carbon, oxygen reduction reaction},
url = {https://www.sciopen.com/article/10.1002/eem2.12084},
doi = {10.1002/eem2.12084},
abstract = {The search for a low-cost metal-free cathode material with excellent mass transfer structure and catalytic activity in oxygen reduction reaction (ORR) is one of the most challenging issues in fuel cells. In this work, nitrogen-rich m-phenylenediamine is introduced into the synthesis of porous carbon spheres to tune the pore structure and nitrogen-doped active sites. As a result, more pyridinic N and pyrrolic N functional species were observed at the interior and surface of the carbon spheres. The introduction of m-phenylenediamine also regulated the nucleating of precursors, an urchin-like mesoporous surface structure ensures point contact and less agglomeration between each particle was obtained. With optimized proportion of micropores/mesopores and improved nitrogen-contained functional species, the ORR activity can be remarkably improved. The half-wave potential of this catalyst could achieve to 0.81 V (versus RHE) which is only 42 mV lower than commercial Pt/C catalyst. Furthermore, the optimized cathode catalyst achieved a 69 mW cm−2 maximum power density when operated in direct methanol fuel cells at room temperature.}
}