Multi-sites synergistic modulation in oxygen reduction electrocatalysis

Menghui Chen; Yongting Chen; Jialin Cai; Zhili Yang; Meihua Tang; Joey Chung-Yen Jung; Shengli Chen; Jiujun Zhang; Shiming Zhang

doi:10.1016/j.jcis.2022.09.008

Multi-sites synergistic modulation in oxygen reduction electrocatalysis

J Colloid Interface Sci. 2023 Jan;629(Pt A):697-705. doi: 10.1016/j.jcis.2022.09.008. Epub 2022 Sep 6.

Authors

Menghui Chen¹, Yongting Chen², Jialin Cai¹, Zhili Yang¹, Meihua Tang³, Joey Chung-Yen Jung¹, Shengli Chen³, Jiujun Zhang¹, Shiming Zhang⁴

Affiliations

¹ Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China.
² School of Chemistry and Chemical Engineering, Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, Wuhan University of Science and Technology, Wuhan 430081, China.
³ College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072, China.
⁴ Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China. Electronic address: smzhang@shu.edu.cn.

PMID: 36099839
DOI: 10.1016/j.jcis.2022.09.008

Abstract

Revealing the types of and interplays among multiple active-sites in iron-nitrogen-carbon (FeNC) 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 FeNC 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 (pyridinicNC), Fe-N₄ and pore defect. It is shown that MF with high N-content is responsible for the formation of the main pyridinicNC 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-N₄ sites, since the interplay between Pc and FePc results in a confinement of Fe-N₄. Zn-salts serve as the pore-forming additives to create sufficient pore defects which can also anchor pyridinicNC and Fe-N₄ 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 FeNC 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.

Keywords: Fe-N(4); Oxygen reduction electrocatalysis; Pore defect; Pyridinic-N-C; Synergy of multiple active-sites.