Multi-sites synergistic modulation in oxygen reduction electrocatalysis

作者：Chen, Menghui; Chen, Yongting; Cai, Jialin; Yang, Zhili; Tang, Meihua; Jung, Joey Chung-Yen; Chen, Shengli; Zhang, Jiujun; Zhang, Shiming^*

来源：Journal of Colloid and Interface Science, 2023, 629: 697-705.

DOI：10.1016/j.jcis.2022.09.008

• Oxygen reduction electrocatalysis
• Synergy of multiple active-sites
• Fe-N-4
• Pyridinic-N-C
• Pore defect

Revealing the types of and interplays among multiple active-sites in iron-nitrogen-carbon (Fe-N-C) materials is of great significance for developing high-performance, Fe-based non-precious metal catalysts for oxygen reduction reaction (ORR). In this paper, a single-atom Fe-N-C catalyst is prepared through high-temperature pyrolyzing of melamine foam (MF), iron phthalocyanine (FePc), phthalocyanine (Pc), and zinc (Zn)-salts composite. The catalyst is found to contain a variety of active-sites, including carbon atom next to pyridinic-N (pyridinic-N-C), Fe-N-4 and pore defect. It is shown that MF with high N -content is responsible for the formation of the main pyridinic-N-C sites and in the meantime acts as the self-sacrificed template for framework of the catalyst. The presence of Pc can facilitate the formation of the predominant Fe-N-4 sites, since the interplay between Pc and FePc results in a confinement of Fe-N-4. Zn-salts serve as the pore-forming additives to create sufficient pore defects which can also anchor pyridinic-N-C and Fe-N-4 structures. The results of density functional theory (DFT) calculations suggest that the multiple active-sites function synergistically to enable high-efficiency ORR electrocatalysis. The optimal Fe-N-C catalyst shows superior ORR activity with a half-wave potential of-0.88 V (vs. RHE), as well as high methanol tolerance and electrochemical stability compared to the commercial carbon -supported platinum (Pt/C) catalyst.

• 单位
  武汉大学; 上海大学