A plasma-assisted approach to enhance density of accessible FeN4 sites for proton exchange membrane fuel cells

Yanrong Li; Liqing Qiao; Shuhu Yin; Xiaoyang Cheng; Chong-Tai Wang; Yanxia Jiang; Shigang Sun

doi:10.1016/j.jcis.2023.05.107

A plasma-assisted approach to enhance density of accessible FeN₄ sites for proton exchange membrane fuel cells

J Colloid Interface Sci. 2023 Oct:647:224-232. doi: 10.1016/j.jcis.2023.05.107. Epub 2023 May 22.

Authors

Yanrong Li¹, Liqing Qiao¹, Shuhu Yin¹, Xiaoyang Cheng¹, Chong-Tai Wang², Yanxia Jiang³, Shigang Sun⁴

Affiliations

¹ State Key Laboratory of Physical Chemistry of Solid Surfaces, Engineering Research Center of Electrochemical Technologies of Ministry of Education, College of Chemistry and Chemical Engineering, and Discipline of Intelligent Instrument and Equipment, Xiamen University, Xiamen 361005, PR China.
² College of Chemistry and Chemical Engineering, Hainan Normal University, Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province, Haikou 571158, PR China.
³ State Key Laboratory of Physical Chemistry of Solid Surfaces, Engineering Research Center of Electrochemical Technologies of Ministry of Education, College of Chemistry and Chemical Engineering, and Discipline of Intelligent Instrument and Equipment, Xiamen University, Xiamen 361005, PR China. Electronic address: yxjiang@xmu.edu.cn.
⁴ State Key Laboratory of Physical Chemistry of Solid Surfaces, Engineering Research Center of Electrochemical Technologies of Ministry of Education, College of Chemistry and Chemical Engineering, and Discipline of Intelligent Instrument and Equipment, Xiamen University, Xiamen 361005, PR China. Electronic address: sgsun@xmu.edu.cn.

PMID: 37247485
DOI: 10.1016/j.jcis.2023.05.107

Abstract

Enhancing the density and utilization of FeN₄ sites can serve as a viable approach to enhance the catalytic efficacy of iron nitrogen carbon (FeNC) catalysts for oxygen reduction reaction (ORR). Herein, we present a plasma-assisted method for enhancing the porosity of nitrogen-doped carbon. Our findings indicate that the ideal ratio of mesopore to micropore area is 0.463. This ratio not only promotes the diffusion of Fe³⁺ but also creates additional active sites for Fe³⁺ loading, leading to an increase in the number of available FeN₄ sites in FeNC electrocatalysts during pyrolysis. The density (76.5 μmol g^-1) and utilization (21.08 %) of d-FeNC-30 are significantly higher than those of FeNC without plasma treatment, with a 2.8-fold and 2-fold increase, respectively. Remarkably, it displays outstanding performance, evidenced by a half-wave potential of 0.835 V (vs. RHE) in a 0.1 M HClO₄ solution and a power density of 0.860 W cm^-2 in proton exchange membrane fuel cells (PEMFCs). The developed plasma-assisted approach for improving the site density (SD) and utilization of FeN₄ provides a new perspective for high-performance ORR FeNC catalysts.

Keywords: Defects; Fe–N–C; Fuel cells; Oxygen reduction reaction; Plasma; Site density.